Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for the Southern California Distinct Vertebrate Population Segment of the Mountain Yellow-Legged Frog (Rana muscosa, 54106-54143 [05-17755]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 70, Number 176 (Tuesday, September 13, 2005)]
[Proposed Rules]
[Pages 54106-54143]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-17755]



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Part II





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



Endangered and Threatened Wildlife and Plants; Proposed Designation of 
Critical Habitat for the Southern California Distinct Vertebrate 
Population Segment of the Mountain Yellow-Legged Frog (Rana muscosa); 
Proposed Rule

Federal Register / Vol. 70, No. 176 / Tuesday, September 13, 2005 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AU30


Endangered and Threatened Wildlife and Plants; Proposed 
Designation of Critical Habitat for the Southern California Distinct 
Vertebrate Population Segment of the Mountain Yellow-Legged Frog (Rana 
muscosa)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
designate critical habitat for the endangered southern California 
distinct vertebrate population segment (DPS) of the mountain yellow-
legged frog (Rana muscosa) pursuant to the Endangered Species Act of 
1973, as amended (Act). We have determined that approximately 8,770 ac 
(3,549 ha) of land containing features essential to the conservation of 
the mountain yellow-legged frog exist in Los Angeles, San Bernardino, 
and Riverside Counties, CA. We are proposing to designate approximately 
8,283 acres (ac) (3,352 hectares (ha)) of streams and riparian areas as 
critical habitat within 3 units in southern California, further divided 
into subunits: Unit 1 (7 subunits) in the San Gabriel Mountains (Los 
Angeles and San Bernardino counties); Unit 2 (3 subunits) in San 
Bernardino Mountains (San Bernardino County); and Unit 3 (4 subunits) 
in the San Jacinto Mountains (Riverside County). Lands being proposed 
as critical habitat are under Federal, local/state, and private 
ownership; no tribal lands are included in this proposed designation. 
This proposed designation includes areas currently known to be occupied 
by the southern California DPS of the mountain yellow-legged frog, as 
well as several areas that were historically occupied, but are 
currently unoccupied. We are proposing to exclude critical habitat from 
approximately 487 ac (197 ha) of non-Federal lands within existing 
Public/Quasi Public (PQP) lands, proposed conceptual reserve design 
lands, and lands targeted for conservation within the Western Riverside 
County Multiple Species Habitat Conservation Plan (MSHCP) Area under 
section 4(b)(2) of the Act.

DATES: We will accept comments from all interested parties until 
November 14, 2005. We must receive requests for public hearings, in 
writing, at the address shown in the ADDRESSES section by October 28, 
2005.

ADDRESSES: If you wish to comment, you may submit your comments and 
materials concerning this proposal by any one of several methods:
    1. You may submit written comments and information to Jim Bartel, 
Field Supervisor, U.S. Fish and Wildlife Service, Carlsbad Fish and 
Wildlife Office, 6010 Hidden Valley Road, Carlsbad, California 92011.
    2. You may hand-deliver written comments to our Office, at the 
above address.
    3. You may send comments by electronic mail (e-mail) to [FW1CFWO--
MYLFPCH@fws.gov]. Please also include ``Attn: mountain yellow-legged 
frog'' in your e-mail subject header and see the Public Comments 
Solicited section below for file format and other information about 
electronic filing.
    1. You may fax your comments to (760) 431-9624.
    Comments and materials received, as well as supporting 
documentation used in the preparation of this proposed rule, will be 
available for public inspection, by appointment, during normal business 
hours at the Carlsbad Fish and Wildlife Office, 6010 Hidden Valley 
Road, Carlsbad, California 92011 (telephone (760) 431-9440).

FOR FURTHER INFORMATION CONTACT: Field Supervisor, Carlsbad Fish and 
Wildlife Office, 6010 Hidden Valley Road, Carlsbad, California 92011, 
(telephone (760) 431-9440; facsimile (760) 431-9624).

SUPPLEMENTARY INFORMATION:

Public Comments Solicited

    We intend that any final action resulting from this proposal will 
be as accurate and as effective as possible. Therefore, comments or 
suggestions from the public, other concerned governmental agencies, the 
scientific community, industry, or any other interested party 
concerning this proposed rule are hereby solicited. Comments 
particularly are sought concerning:
    (1) Specific information on the southern California distinct 
vertebrate population segment (DPS) of the mountain yellow-legged frog: 
i.e., the locations of known occurrences of individuals or 
subpopulations, the dispersal behavior and distances of adults, 
juveniles and tadpoles, the developmental time of tadpoles and their 
habitat requirements throughout the year, genetic information in the 
mountain yellow-legged frog, recreation impacts, impacts of non-native 
predators;
    (2) Specific information as to whether the physical and biological 
features we have identified essential to its conservation are accurate 
and whether they exist on those areas we have identified as occupied;
    (3) If those unoccupied areas proposed to be designated are all 
essential to the conservation to the species;
    (4) The proposed exclusion of habitat on non-Federal lands within 
existing Public/Quasi Public (PQP) lands, proposed conceptual reserve 
design lands, and lands targeted for conservation within the Western 
Riverside County Multiple Species Habitat Conservation Plan (MSHCP) 
under section 4(b)(2) of the Act. Please provide information 
demonstrating the conservation benefits of including these lands exceed 
the benefits of excluding these lands. If the Secretary determines the 
benefits of including the lands outweigh the benefits of excluding 
them, they will not be excluded from critical habitat;
    (5) Land use designations and current or planned activities in the 
subject areas and their possible impacts on proposed critical habitat;
    (6) Any foreseeable economic, national security, or other potential 
impacts resulting from the proposed designation and, in particular, any 
impacts on small entities; and
    (7) Whether our approach to designating critical habitat could be 
improved or modified in any way to provide for greater public 
participation and understanding, or to assist us in accommodating 
public concerns and comments.
    If you wish to comment, you may submit your comments and materials 
concerning this proposal by any one of several methods (see ADDRESSES). 
Please submit Internet comments to [FW1CFWO--MYLFPCH@fws.gov] in ASCII 
file format and avoid the use of special characters or any form of 
encryption. Please also include ``Attn: mountain yellow-legged frog'' 
in your e-mail subject header and your name and return address in the 
body of your message. If you do not receive a confirmation from the 
system that we have received your Internet message, contact us directly 
by calling our Carlsbad Fish and Wildlife Office at phone number 760/
431-944. Please note that the Internet address [FW1CFWO--
MYLFPCH@fws.gov] will be closed out at the termination of the public 
comment period.
    Our practice is to make comments, including names and home 
addresses of respondents, available for public review during regular 
business hours.

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Individual respondents may request that we withhold their home 
addresses from the rulemaking record, which we will honor to the extent 
allowable by law. There also may be circumstances in which we would 
withhold from the rulemaking record a respondent's identity, as 
allowable by law. If you wish us to withhold your name and/or address, 
you must state this prominently at the beginning of your comment. 
However, we will not consider anonymous comments. We will make all 
submissions from organizations or businesses, and from individuals 
identifying themselves as representatives or officials of organizations 
or businesses, available for public inspection in their entirety. 
Comments and materials received will be available for public 
inspection, by appointment, during normal business hours at the above 
address.

Designation of Critical Habitat Provides Little Additional Protection 
to Species

    In 30 years of implementing the Act, the U.S. Fish and Wildlife 
Service (Service) has found that the designation of statutory critical 
habitat provides little additional protection to most listed species, 
while consuming significant amounts of available conservation 
resources. The Service's present system for designating critical 
habitat has evolved since its original statutory prescription into a 
process that provides little real conservation benefit, is driven by 
litigation and the courts rather than biology, limits our ability to 
fully evaluate the science involved, consumes enormous agency 
resources, and imposes huge social and economic costs). The Service 
believes that additional agency discretion would allow our focus to 
return to those actions that provide the greatest benefit to the 
species most in need of protection.
    In this current proposed critical habitat rule, we have determined 
that the identification and conservation of unoccupied habitat is 
necessary for the long-term persistence of the mountain yellow-legged 
frog. In the case of this species, because we have determined it 
necessary to propose critical habitat in unoccupied areas, the critical 
habitat designation will provide a benefit to the species.

Role of Critical Habitat in Actual Practice of Administering and 
Implementing the Act

    While attention to and protection of habitat is paramount to 
successful conservation actions, we have consistently found that, in 
most circumstances, the designation of critical habitat is of little 
additional value for most listed species, yet it consumes large amounts 
of conservation resources. Sidle (1987) stated, ``Because the Act can 
protect species with and without critical habitat designation, critical 
habitat designation may be redundant to the other consultation 
requirements of section 7.'' Currently, of the 1,253 listed species in 
the U.S. under the jurisdiction of the Service, only 471 species (38 
percent) have designated critical habitat. We address the habitat needs 
of all 1,253 listed species through conservation mechanisms such as 
listing, section 7 consultations, the section 4 recovery planning 
process; the section 9 protective prohibitions of unauthorized take, 
section 6 funding to the States, and the section 10 incidental take 
permit process. The Service believes that it is these measures that may 
make the difference between extinction and survival for many species.
    We note, however, that a recent Ninth Circuit judicial opinion, 
Gifford Pinchot Task Force v. United States Fish and Wildlife Service, 
has invalidated the Service's regulation defining destruction or 
adverse modification of critical habitat. In response, on December 9, 
2004, the Director issued guidance to be used in making section 7 
adverse modification determinations. This critical habitat designation 
does not use the invalidated regulation in our consideration of 
critical habitat's benefits.

Procedural and Resource Difficulties in Designating Critical Habitat

    We have been inundated with lawsuits for our failure to designate 
critical habitat, and we face a growing number of lawsuits challenging 
critical habitat determinations once they are made. These lawsuits have 
subjected the Service to an ever-increasing series of court orders and 
court-approved settlement agreements, compliance with which now 
consumes nearly the entire listing program budget. This leaves the 
Service with little ability to prioritize its activities to direct 
scarce listing resources to the listing program actions with the most 
biologically urgent species conservation needs.
    The consequence of the critical habitat litigation activity is that 
limited listing funds are used to defend active lawsuits, to respond to 
Notices of Intent (NOIs) to sue relative to critical habitat, and to 
comply with the growing number of adverse court orders. As a result, 
listing petition responses, the Service's own proposals to list 
critically imperiled species, and final listing determinations on 
existing proposals are all significantly delayed.
    The accelerated schedules of court ordered designations have left 
the Service with almost no ability to provide for adequate public 
participation or to ensure a defect-free rulemaking process before 
making decisions on listing and critical habitat proposals due to the 
risks associated with noncompliance with judicially-imposed deadlines. 
This in turn fosters a second round of litigation in which those who 
fear adverse impacts from critical habitat designations challenge those 
designations. The cycle of litigation appears endless, is very 
expensive, and in the final analysis provides relatively little 
additional protection to listed species.
    The costs resulting from the designation include legal costs, the 
cost of preparation and publication of the designation, the analysis of 
the economic effects and the cost of requesting and responding to 
public comment, and in some cases the costs of compliance with the 
National Environmental Policy Act (NEPA). None of these costs result in 
any benefit to the species that is not already afforded by the 
protections of the Act enumerated earlier, and they directly reduce the 
funds available for direct and tangible conservation actions.

Background

    Please refer to the final listing rule published in the Federal 
Register on July 2, 2002 (67 FR 44382) for a detailed discussion on the 
taxonomic history and description of the southern California distinct 
vertebrate population segment (DPS) of the mountain yellow-legged frog 
(Rana muscosa), hereafter referred to as the mountain yellow-legged 
frog. It is our intent in this document to reiterate and discuss only 
those topics directly relevant to the development and designation of 
critical habitat or relevant information obtained since the final 
listing.
    The mountain yellow-legged frog is in the family of true frogs, 
Ranidae, which consists of frogs that are more closely tied to water 
bodies for breeding and foraging than other frog or toad species. 
Mountain yellow-legged frogs are diurnal frogs, occupying rocky and 
shaded streams with cool waters originating from springs and snowmelt. 
Many of the streams in which they historically occurred have a 
relatively steep gradient with large boulders in the streambeds 
(Stebbins 1951).
    Historically, mountain yellow-legged frogs in southern California 
were documented over a wide elevation range, from 1,214 ft to 7,513 ft 
(370 m

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to 2,290 m) (Jennings and Hayes 1994a), and in a wide variety of 
wetland habitats, including lakes, rivers, creeks, ponds, and marshes 
(Zweifel 1955, Mullally 1959, Schoenherr 1976, Jennings 1994a, b, 
Vredenburg et al. 2005).
    Mountain yellow-legged frogs historically occurred in streams on 
both the desert and coastal slopes of the San Gabriel, San Bernardino, 
San Jacinto, and Palomar Mountains in Los Angeles, San Bernardino, 
Riverside, and San Diego counties (Zweifel 1955). Despite the close 
proximity of the Transverse Mountain Ranges to highly populated areas 
such as Los Angeles, Riverside, and San Diego, the vertebrate fauna has 
been relatively little studied, particularly in the San Gabriel 
Mountains (Jennings 1994). Over 40 years ago, Schoenherr (1976) and 
Zweifel (1955) described the distribution of frogs in the region, but 
their studies were not encompassing; e.g. in the San Gabriel Mountains, 
their works were conducted in the southern and western areas. Little to 
no observations were collected in the 1980's, but during the 1990's, 
Jennings (1993, 1994, 1995, 1998, 1999) surveyed for the mountain 
yellow-legged frog extensively in the region. This work was 
subsequently resumed by USGS, who has conducted annual surveys for 
mountain yellow-legged frog in southern California since 2000.
    In the most recent USGS survey report on the mountain yellow-legged 
frog in southern California, Backlin et al. (2004) used historical 
records to compare the locations of where frogs previously were found 
to the locations of the current, extant populations and concluded that 
between the 1900's and today, it is evident that the mountain yellow-
legged frog has disappeared from nearly all of its former range in 
southern California. Between 2000 and 2003, USGS, USFS, and CDFG 
conducted extensive surveys for mountain yellow-legged frogs at their 
historical locations and other areas with suitable habitat. Backlin et 
al. (2004) gave the overall survey results: mountain yellow-legged 
frogs are currently known to occur in only 8 areas in southern 
California, and all were located in isolated headwater streams (Backlin 
et al. 2004). Most of these populations occur above (upstream of) a 
barrier, natural or artificial, which limits upstream movement by fish 
(cf. Backlin et al. 2004; A. Backlin, USGS, pers. comm. 2005). In the 
Palomar Mountains, where mountain yellow-legged frog previously 
occurred, no recent, exhaustive surveys have been conducted (Backlin et 
al. 2004). Additional surveys need to be conducted in areas with 
suitable aquatic habitat that includes streams, creeks and pools, but 
also springs, seeps marshes, and small tributaries, so that 
undocumented populations are not inadvertently overlooked (Backlin et 
al. 2004).
    The final listing rule (67 FR 44382) described the mountain yellow-
legged frog as occupying five streams in the San Gabriel Mountains: (1) 
Bear Gulch-East Fork San Gabriel River (referred to in this rule as San 
Gabriel River, East Fork, Bear Gulch); (2) Vincent Gulch-East Fork San 
Gabriel River (referred to in this rule as San Gabriel River, East 
Fork, Vincent Gulch); (3) South Fork-Big Rock Creek (referred to in 
this rule as Big Rock Creek, South Fork); (4) Little Rock Creek, and 
(5) Devil's Canyon-West Fork San Gabriel River. The final listing rule 
also recognized one population within the San Bernardino Mountains 
(City Creek-East Fork), and one population in the San Jacinto Mountains 
(Fuller Mill Creek (referred to in this rule as San Jacinto River, 
North Fork, Fuller Mill Creek)). The mountain yellow-legged frog is 
believed to be extirpated from Palomar Mountain (Jennings and Hayes 
1994a).
    In the proposed and final rules listing the southern California DPS 
of the mountain yellow-legged frog as endangered, we identified 
additional streams where the DPS had previously been known to occur, 
but were not found in surveys conducted in 2001 (64 FR 71714; 67 FR 
44382). These streams where mountain yellow-legged frogs had been 
observed included: Alder Gulch-East Fork San Gabriel River in the San 
Gabriel Mountains (referred to in this rule as San Gabriel River, East 
Fork, Alder Gulch), where they were last seen in 1998 (Jennings 1998); 
the North Fork of San Jacinto River, last seen in 1999; Hall Canyon 
(referred to in this rule as Indian Creek at Hall Canyon), last seen in 
1995; and Dark Canyon in the San Jacinto Mountains, where frogs have 
been observed in 2005. The population in Dark Canyon was recently 
rediscovered in 2003 by biologists from the California Department of 
Fish and Game (CDFG) and the San Bernardino National Forest (Backlin et 
al. 2004). Prior to the rediscovery of this population, the last 
observation of the mountain yellow-legged frog in Dark Canyon was in 
1999.
    Barton Creek and Day Canyon were known to be occupied by the 
mountain yellow-legged frog prior to the listing in 2002, but were not 
discussed in either the proposed or final listing rules. Approximately 
50 individual adults were observed in Barton Creek, East Fork in 1993 
(CNDDB 2005), when water flowed well in the creek (R. McKernan, dir. 
San Bernardino County Museum, pers. comm. 2005). Mountain yellow-legged 
frogs were first observed in Day Canyon in 1959 (Los Angeles County 
Museum), and re-sighted there in 1994 (CNDDB 2005). In 2003, the USGS 
conducted a single visit survey of a portion of Day Canyon, and did not 
locate any mountain yellow-legged frogs, but did note the occurrence of 
rainbow trout (Onchorhynchus mykiss) (Backlin et al. 2004).
    In summary, we identified the following streams as occupied at the 
time of listing: (a) In the San Gabriel Mountains: the East Fork of the 
San Gabriel River including Bear Gulch (67 FR 44382), Prairie Creek (64 
FR 71714), Vincent Gulch (64 FR 71714, 67 FR 44382), Alder Creek--East 
Fork (64 FR 71714; referred to here as Alder Gulch), Devil's Canyon (64 
FR 71714, 67 FR 44382), Big Rock Creek (67 FR 44382) and Little Rock 
Creek (64 FR 71714, 67 FR 44382); (b) In the San Bernardino Mountains: 
the East Fork, City Creek (64 FR 71714, 67 FR 44382) which is currently 
assumed to be unoccupied; (c) In the San Jacinto Mountains: four 
tributaries in the upper reaches of the North Fork, San Jacinto River 
on Mount San Jacinto: Dark Canyon (64 FR 71714, 67 FR 44382), Hall 
Canyon (64 FR 71714, 67 FR 44382; referred to here as Indian Creek at 
Hall Canyon), Fuller Mill Creek (64 FR 71714, 67 FR 44382), and the 
main North Fork, San Jacinto River (64 FR 71714).
    Subsequent to listing the species, we identified the following 
additional streams as also occupied: (a) In the San Gabriel Mountains: 
the East Fork of the San Gabriel River: the main stem of the San 
Gabriel River, East Fork at the confluence of Fish Fork to below the 
confluence of Iron Fork, the lower reaches of the tributaries Iron Fork 
and Fish Fork, and Day Canyon in San Bernardino National Forest; (b) in 
the San Bernardino Mountains: the East Fork of Barton Creek (San 
Bernardino National Forest), and the East Fork of City Creek, and; (c) 
in the San Jacinto Mountains: an unnamed side tributary of the North 
Fork of the San Jacinto River in Dark Canyon.
    This rule also proposes some streams that were historically 
occupied and currently assumed to be unoccupied, because we believe 
these streams are essential to the conservation of the species. These 
are: (a) In the San Gabriel Mountains (Angeles National Forest): Bear 
Creek (located north of the West Fork of the San Gabriel River), and 
the East Fork of Iron Fork, a tributary to the East Fork of the San 
Gabriel River; (b) In the San Bernardino Mountains: the

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upper reaches of the North Fork of Whitewater River (San Bernardino 
National Forest); and (c) In the San Jacinto Mountains (San Bernardino 
National Forest): Tahquitz Creek (uppermost reaches, including Willow 
Creek tributary), and Andreas Creek (uppermost reaches) both within the 
San Jacinto Wilderness area.
    As discussed in the final listing rule (67 FR 44382), Jennings and 
Hayes (1994) estimated that mountain yellow-legged frogs have been 
extirpated from more than 99 percent of their previously documented 
range in southern California. The mechanisms causing the declines of 
ranid frogs in the western United States are not well understood and 
are certain to vary somewhat among species. The two most common and 
well-supported hypotheses for widespread extirpation of western ranid 
frogs are: (1) Past habitat destruction related to activities such as 
logging, mining, and habitat conversions for water development, 
irrigated agriculture, and commercial development (Hayes and Jennings 
1986, 61 FR 25813); and (2) non-native predators and competitors such 
as introduced trout and bullfrogs (Hayes and Jennings 1986, Bradford 
1989, Knapp 1996, Kupferberg 1997). There is now a growing body of 
evidence that the mountain yellow-legged frog is incompatible with non-
native trout, bullfrog and crayfish (Hayes and Jennings 1986, Bradford 
1989, Bradford et al. 1994, Knapp and Matthews 2000, Knapp et al 2003, 
Backlin et al. 2004, Vredenburg 2004).
    Studies of the distributions of introduced salmonids (rainbow trout 
and brook trout Salvelinus fontinalis) and mountain yellow-legged frogs 
have shown that introduced trout have had negative impacts on mountain 
yellow-legged frogs over much of the Sierra Nevada (Bradford 1989, 
Knapp 1996, Knapp and Matthews 2000). Vredenburg (2002) demonstrated 
that this is due primarily to predation on tadpoles. Trout are known 
predators of ranid frogs (Hayes and Jennings 1986, Backlin et al. 
2004), and there is evidence that introduced trout restrict the 
distribution and abundance of mountain yellow-legged frogs (Bradford 
1989, Bradford et al 1994, Knapp and Matthews 2000, Knapp et al. 2003, 
Backlin et al. 2004). Today, non-native trout persist at seven of the 
eight known locations where the mountain yellow-legged frog occurs in 
southern California (Backlin et al. 2004, Stewart et al. 2000). 
Further, Bradford (1989) and Bradford et al. (1993) concluded that 
introduced trout eliminate many populations of mountain yellow-legged 
frogs and the presence of trout in intervening streams sufficiently 
isolates other frog populations such that recolonization after 
stochastic (random) local extirpations is essentially impossible. 
Virtually all streams in the mountains of southern California contain 
populations of introduced rainbow trout, and, until recently, trout 
were routinely released in several of the occupied streams. The CDFG, 
which operates the Mojave and Fillmore fish hatcheries, has stated that 
no stocked sites and areas accessible to stocked fish overlap with 
areas where the mountain yellow-legged frog is known to occur (Service 
in litt. 2005). The CDFG has also been working with the U.S. Forest 
Service (USFS) to refrain from stocking certain streams and to assess 
the potential construction of barriers. In their latest report on 
mountain yellow-legged frog, the USGS (Backlin et al. 2004) recommend 
continuing trout removal efforts in all streams where mountain yellow-
legged frog occur in southern California, and expanding these efforts 
also to the West Fork of City Creek. Conservation of this species may 
require management of non-native trout populations within proposed 
critical habitat and continued protection of those lands proposed for 
critical habitat that do not contain non-native trout.
    Two pathogens are of primary concern for the conservation of 
mountain yellow-legged frogs in southern California. The ``red-leg'' 
disease contributed to the loss of a Sierra Nevada population (Bradford 
1991). Another pathogen that is of concern to scientists studying 
amphibian declines is the chytrid fungus (Batrachochytrium 
dendrobatidis). Chytrid fungus may be seriously affecting amphibians 
around the world, and has recently been discovered on larval and 
recently metamorphosed mountain yellow-legged frogs in the Sierra 
Nevada Mountains (Fellers et al. 2001). Currently, chytrid fungal 
disease does not seem to be plaguing the remaining populations (Backlin 
et al. 2004).
    In addition to the threats posed by the presence of non-native 
trout and pathogens, some recreational activities, which involve human 
activity in or adjacent to streams where the species is still extant, 
have also been identified as potentially negatively impacting the 
mountain yellow-legged frogs (Stewart et al. 2000). For example, 
logging activity, recreational mining, or heavy trampling may alter 
and/or decrease the presence of habitat structure within a stream, 
alter pool substrate, erode stream banks, or reduce riparian 
vegetation, negatively affecting various life history stages and 
essential behaviors of the mountain yellow-legged frog. Conservation of 
this species may require special management in areas where heavy 
recreational use overlaps with occupied habitat.
    Chance, catastrophic events which, while normal for the environment 
in which the frog lives, greatly endanger the remaining, localized 
populations; i.e. fires, droughts, and floods. The area has experienced 
floods in winter 1968-69, which decimated many of the frog populations 
formerly abundant in the region (Jennings and Hayes 1994a, b). Drought 
conditions have prevailed for long periods during the years 1995-2004, 
with 2002 the height of the drought, and several major fires have 
occurred (1997, 2003; Backlin et al. 2004). However, to alleviate the 
most immediate threats to the southern California mountain yellow-
legged frog, it is possible to reduce or eradicate exotic species, 
prevent direct human impacts and take precautions to prevent the spread 
of diseases (Backlin et al. 2004). Alleviating the most pressing 
threats in the occupied areas will allow those populations to expand 
into currently unoccupied areas which will also be managed and 
protected allowing even greater population expansion to such an extent 
that naturally occurring threats will not pose as great a danger.

Previous Federal Actions

    Please refer to the final listing rule for a summary of previous 
Federal actions prior to the listing of the southern California of the 
mountain yellow-legged frog as endangered July 2, 2002 (67 FR 44382). 
At the time of listing, we concluded that designating critical habitat 
was prudent; however, we deferred the critical habitat designation to 
allow us to concentrate our limited resources on higher priority 
critical habitat designations and other listing actions, while allowing 
us to put in place protections needed for the conservation of the 
southern California mountain yellow-legged frog without further delay. 
This action was consistent with section 4(b)(6)(C)(i) of the Act, which 
states that final listing decisions may be issued without concurrent 
designation of critical habitat if it is necessary for the conservation 
of the species that the listing determination be promptly published (67 
FR 44382).
    On August 19, 2004, the Center for Biological Diversity filed a 
lawsuit in the U.S. District Court for the Central District of 
California challenging the Service's failure to designate critical 
habitat for the southern California mountain yellow-legged frog (Case 
No. EDCV 04-01041-VAP). On December

[[Page 54110]]

20, 2004, the District Court granted the Center's motion for summary 
judgment and ordered the Service to publish a proposed critical habitat 
rule for the mountain yellow-legged frog by September 1, 2005, and a 
final critical habitat rule by September 1, 2006. This proposed rule 
complies with the Court's order.

Critical Habitat

    Critical habitat is defined in section 3 of the Act as--(i) the 
specific areas within the geographic area occupied by a species, at the 
time it is listed in accordance with the Act, on which are found those 
physical or biological features (I) essential to the conservation of 
the species and (II) that may require special management considerations 
or protection; and (ii) specific areas outside the geographic area 
occupied by a species at the time it is listed, upon a determination 
that such areas are essential for the conservation of the species. 
``Conservation'' means the use of all methods and procedures that are 
necessary to bring an endangered or a threatened species to the point 
at which listing under the Act is no longer necessary.
    Critical habitat receives protection under section 7 of the Act 
through the prohibition against destruction or adverse modification of 
critical habitat with regard to actions carried out, funded, or 
authorized by a Federal agency. Section 7 requires consultation on 
Federal actions that are likely to result in the destruction or adverse 
modification of critical habitat. The designation of critical habitat 
does not affect land ownership or establish a refuge, wilderness, 
reserve, preserve, or other conservation area. Such designation does 
not allow government or public access to private lands.
    To be included in a critical habitat designation, the habitat 
within the area occupied by the species at the time of listing must 
first have features that are ``essential to the conservation of the 
species.'' Critical habitat designations identify, to the extent known 
using the best scientific and commercial data available, habitat areas 
that provide for the essential life cycle needs of the species (i.e., 
areas on which are found the primary constituent elements (PCEs), as 
defined at 50 CFR 424.12(b)).
    Habitat occupied at the time of listing may be included in critical 
habitat only if the essential features (PCEs) are actually present 
thereon and may require special management considerations or 
protection. Thus, we do not include areas where existing management is 
sufficient to protect and manage the habitat in a manner equal to the 
protections provided by the designation and consistent with the court's 
direction in Gifford Pinchot. Our interpretation of that requirement 
pending a new rulemaking is included in the Director's December 9, 
2004, memorandum, referenced in the preamble. (As discussed below, such 
areas may also be excluded from critical habitat pursuant to section 
4(b)(2).) Accordingly, when the best available scientific and 
commercial data do not demonstrate that the conservation needs of the 
species so require, we will not designate critical habitat in areas 
outside the geographic area occupied by the species at the time of 
listing. Specific areas outside the geographic area occupied by a 
species at the time it is listed may only be included in a critical 
habitat designation if the Secretary determines that such areas are 
essential for the conservation of the species. In this rule, we have 
proposed for inclusion in the critical habitat designation some areas 
not known to be occupied at the time of listing which we have 
determined are essential for the conservation of the species.
    The Service's Policy on Information Standards Under the Endangered 
Species Act, published in the Federal Register on July 1, 1994 (59 FR 
34271), and Section 515 of the Treasury and General Government 
Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658) 
and the associated Information Quality Guidelines issued by the 
Service, provide criteria, establish procedures, and provide guidance 
to ensure that decisions made by the Service represent the best 
scientific and commercial data available. They require Service 
biologists to the extent consistent with the Act and with the use of 
the best scientific and commercial data available, to use primary and 
original sources of information as the basis for recommendations to 
designate critical habitat. When determining which areas to designate 
as critical habitat, a primary source of information is generally the 
listing rule for the species. Additional information sources include 
the recovery plan for the species, articles in peer-reviewed journals, 
conservation plans developed by States and counties, scientific status 
surveys and studies, biological assessments, or other unpublished 
materials and expert opinion or personal knowledge. All information is 
used in accordance with the provisions of Section 515 of the Treasury 
and General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 
106-554; H.R. 5658) and the associated Information Quality Guidelines 
issued by the Service.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific data available. Habitat is often 
dynamic, and species may move from one area to another over time. 
Furthermore, we recognize that designation of critical habitat may not 
include all of the habitat areas that may eventually be determined to 
be necessary for the recovery of the species. Conversely, local 
conservation actions may occur that provide for special management and 
protection equal to that of critical habitat, removing the necessity of 
designation. For these reasons, critical habitat designations do not 
signal that habitat outside the designation is unimportant or may not 
be required for recovery of the mountain yellow-legged frog, or that 
the critical habitat designation itself is immutable.
    Areas that support populations of the mountain yellow-legged frog 
in southern California, but outside the critical habitat designation 
will continue to be subject to conservation actions that may be 
implemented under section 7(a)(1), and to the regulatory protections 
afforded by the section 7(a)(2) jeopardy standard and the section 9 
take prohibition, as determined on the basis of the best available 
information at the time of the action. We specifically anticipate that 
federally funded or assisted projects affecting listed species outside 
their designated critical habitat areas may still result in jeopardy 
findings in some cases. Similarly, critical habitat designations made 
on the basis of the best available information at the time of 
designation will not control the direction and substance of future 
recovery plans, habitat conservation plans, or other species 
conservation planning efforts particularly if new information available 
to these planning efforts calls for a different outcome.

Methods

    As required by section 4(b)(1)(A) of the Act, we used the best 
scientific and commercial data available in determining areas of 
habitat that contain features essential to the conservation of the 
mountain yellow-legged frog. This includes information from the 
proposed listing rule (64 FR 71714), final listing rule (67 FR 44382), 
data from research and survey observations published in peer-reviewed 
articles, site visits, regional Geographic Information System (GIS) 
layers, soil, and species coverages, and data compiled in the 
California Natural Diversity Database (CNDDB).

[[Page 54111]]

    We have also reviewed available information that pertains to the 
ecology, natural history, and habitat requirements of this species. 
This material included information and data in reports submitted during 
section 7 consultations; research published in peer-reviewed articles 
and technical reports by the U.S. Geological Survey (USGS) and the 
USFS; and regional GIS coverages. We are not proposing to designate as 
critical habitat any areas outside of the geographic area presently 
occupied by the species in the San Gabriel, San Bernardino and San 
Jacinto mountains; however, the area proposed for designation includes 
areas for which we have no data demonstrating current occupancy, but 
for which we have historic occupancy data.

Primary Constituent Elements

    In accordance with section 3(5)(A)(i) of the Act and regulations at 
50 CFR 424.12, in determining which areas to propose as critical 
habitat, we are required to base critical habitat determinations on the 
best scientific and commercial data available and to identify those 
physical and biological features (primary constituent elements (PCEs)) 
that are essential to the conservation of the species, and that may 
require special management considerations or protection. These include, 
but are not limited to: space for individual and population growth and 
for normal behavior; food, water, air, light, minerals, or other 
nutritional or physiological requirements; cover or shelter; sites for 
breeding, reproduction, and rearing (or development) of offspring.
    The specific primary constituent elements essential for the 
conservation of the southern California mountain yellow-legged frog are 
derived from the abiotic and biotic needs of the species as described 
below.

Space for Individual and Population Growth and for Normal Behavior

    The permanent water sources such as streams, rivers, perennial 
creeks, permanent plunge pools within intermittent creeks, and pools 
are needed for individual and population growth. These permanent water 
sources (PCE 1) provide breeding sites and shelter for the 
mountain yellow-legged frog. Permanent water sources providing for 
perennial flows are needed for egg-laying and tadpole growth and 
survival, and must provide adequate water quality for adult and 
offspring of the mountain yellow-legged frog. Such water sources and 
their associated riparian and upland habitat also provide habitat for 
aquatic invertebrates that are used as a food source by adult mountain 
yellow-legged frogs, and for the benthic algae and diatoms that are fed 
upon by larval frogs.

Food, Water, Air, Light, or Other Nutritional or Physiological 
Requirements

    A wide variety of invertebrates including beetles (Coleoptera), 
ants (Formididae), bees (Apoidea), wasps (Hymenoptera), flies 
(Diptera), true bugs (Hemiptera), and dragonflies (Odonata) have been 
found in the stomachs of adult mountain yellow-legged frogs (Long 
1970). Terrestrial insects and adult stages of aquatic insects may be 
the preferred food for adult mountain yellow-legged frog (Bradford 
1983); larger frogs consume more aquatic true bugs probably because of 
their more aquatic behavior (Jennings and Hays 1994).
    The riparian zone, with the associated vegetation canopy (PCE 
2), is necessary to maintain the prey base needed for the 
nutritional requirements of the mountain yellow-legged frog. Larvae 
graze on algae and diatoms in the silt along rocky bottoms in streams 
and ponds (Zeiner et al. 1988). An open or semi-open canopy of riparian 
vegetation (canopy overstory not exceeding 85 percent) is needed to 
ensure that adequate sunlight reaches the stream to allow for basking 
behavior and for photosynthesis by benthic algae and diatoms that are 
food resources for larval mountain yellow-legged frog.

Cover or Shelter

    Mountain yellow-legged frogs are preyed upon by the western 
terrestrial garter snake (Thamnophis elegans), Brewer's blackbird 
(Euphagus cyanocephalus), Clark's nutcrackers (Nucifraga columbiana), 
and coyotes (Canis latrans) (USFS 2002). Pools with bank overhangs, 
downfall logs or branches, and/or rocks (PCEs 1 and 
2) provide cover from predators for mountain yellow-legged 
frogs.

Sites for Breeding, Reproduction, and Rearing of Offspring

    In southern California, the mountain yellow-legged frog occupies 
streams in the chaparral belt (Zweifel 1955), and cool and cold, rocky, 
mountain watercourses shaded by trees, rocks, and other shelter, where 
the flow comes from springs and snowmelt (Jennings and Hayes 1994b) 
(PCEs 1 and 2). California fan palms (Washingtonia 
filifera), and mesquite (Prosopis spp.) dominate the mountain yellow-
legged frog's habitat at lower elevations, and, in other areas, habitat 
is dominated by white alders (Alnus rhombifolia), willows, sycamore, 
conifers and maples (Jennings and Hayes 1994b, Backlin et al. 2004). 
Open gravel banks and rocks projecting above the water may provide 
sunning posts (Zweifel 1955). Many of the streams in which they 
occurred historically and currently occupy have a relatively steep 
gradient and large boulders in the stream beds (Stebbins 1951). 
Although knowledge pertaining to the specific habitat requirements of 
mountain yellow-legged frogs in southern California is limited, the 
presence of water year-round is known to be necessary for both 
reproduction and for hydration of juveniles and adults. In southern 
California, mountain yellow-legged frogs historically ranged from 1,214 
ft to 7546 ft (370 m to 2,300 m) in elevation (Jennings and Hayes 
1994a, 1994b).

Historic and Geographic Distribution of the Species

    The occupied streams that are proposed for designation contain 
physical and biological features that are representative of the 
historic and geographical distribution of the species. The unoccupied 
streams that are proposed for designation were all historically 
occupied and will decrease the degree of fragmentation within the 
current geographic distribution of the DPS.

Primary Constituent Elements

    Pursuant to our regulations, we are required to identify primary 
constituent elements essential to the conservation of the mountain 
yellow-legged frog, together with the proposed designation of critical 
habitat that contains features essential to the conservation of the 
species. In identifying primary constituent elements, we used the best 
available scientific and commercial data and information. Although the 
physical ranges described below may not capture all of the variability 
that is inherent in natural systems, these ranges best represent the 
physical and biological features essential to the conservation of the 
southern California DPS of the mountain yellow-legged frog in the 
occupied areas proposed for designation. In order to conserve this 
species, we believe that it will be necessary to designate critical 
habitat in areas currently unoccupied by the species, please see our 
discussion of Criteria Used to Identify Critical Habitat and Unit 
Descriptions sections below for further discussion of unoccupied 
habitat.
    The primary constituent elements determined to be essential to the 
conservation of the southern California

[[Page 54112]]

mountain yellow-legged frog are the following:
    1. Water source(s) found between 1,214 ft (370 m) to 7,546 ft 
(2,300 m) in elevation that are permanent, to ensure that aquatic 
habitat for the species is available year-round. Water sources include, 
but are not limited to streams, rivers, perennial creeks (or permanent 
plunge pools within intermittent creeks), pools (i.e., a body of 
impounded water that is contained above a natural dam) and other forms 
of aquatic habitat. The water source should maintain a natural flow 
pattern including periodic natural flooding. Aquatic habitats that are 
used by mountain yellow-legged frog for breeding purposes must maintain 
water during the entire tadpole growth phase (which can be from 1-4 
years duration). During periods of drought, or less than average 
rainfall, these breeding sites may not hold water long enough for 
individuals to complete metamorphosis, but they would still be 
considered essential breeding habitat in wetter years. Further, the 
aquatic habitat should include:
    a. Bank and pool substrates consisting of varying percentages of 
soil or silt, sand, gravel cobble, rock, and boulders;
    b. Water chemistry with a pH generally 6.6 to 9, dissolved oxygen 
varying from 23 to 28 percent and water temperatures during summer 
(June through August) ranging between 4.0 and 30.3 degrees Celsius;
    c. Streams or stream reaches between known occupied sites that can 
function as corridors for adults and frogs for movement between aquatic 
habitats used as breeding and/or foraging sites.
    2. Riparian habitat and upland vegetation (e.g. ponderosa pine, 
montane hardwood-conifer, montane riparian woodlands, and chaparral) 
extending 262 feet (80 m) from each side of the centerline of each 
identified stream and its tributaries, that provides areas for feeding 
and movement of mountain yellow-legged frog, with a canopy overstory 
not exceeding 85 percent that allows sunlight to reach the stream and 
thereby providing basking areas for the species.

Criteria Used To Identify Critical Habitat

    We are proposing to designate critical habitat on lands that we 
have determined to contain habitat with features essential to the 
conservation of the mountain yellow-legged frog. These areas have 
sufficient primary constituent elements described above to enable the 
mountain yellow-legged frog to carry out its essential life processes.
    The currently occupied habitat for the mountain yellow-legged frog 
is highly limited and isolated. The population estimates are all 
extremely small, with no stream having an estimated population size 
exceeding 100 breeding adults, and an overall total estimate of 
approximately 183 adults surviving in 2003 (including City Creek, East 
Fork; Backlin et al. 2004). This DPS is at a high risk of extinction 
and is highly susceptible to stochastic events (Backlin et al. 2004). 
As such, all occupied areas are proposed as critical habitat.
    We have defined occupied proposed critical habitat as: (a) Those 
streams known to be occupied by the mountain yellow-legged frog at the 
time of listing (1987-2002); (b) the riparian, upland and aquatic 
habitats 262 ft (80 m) from the centerline of the stream including 
tributaries; and (c) aquatic habitats within 4,905 ft (1,495 m) 
upstream from the upstream-most occurrence and 4,905 ft (1,495 m) 
downstream from the downstream-most occurrence on the main stem of the 
river or creek known to be occupied, including any tributary that flows 
into it (see the following sections for explanation of the scientific 
basis for the chosen values). To delineate the proposed units of 
occupied critical habitat, we plotted on maps all occurrences records 
of mountain yellow-legged frog as points and polygons along streams 
that were occupied at the time of listing. We then delineated the 
riparian and upland areas that mountain yellow-legged frogs use 
bordering the stream, as well as the upstream and downstream range of 
movement, as defined under (c) above.

Occupied by the Mountain Yellow-Legged Frog at the Time of Listing

    We used the proposed and final listing rules; reports prepared by 
the USGS, the USFS; the California Department of Fish and Game (CDFG), 
the CNDDB, researchers, and consultants; and available information to 
determine the location of specific areas within the geographical area 
occupied by the southern California mountain yellow-legged frog at the 
time of listing (``occupied at the time of listing'' is defined as the 
time period 1987-2002).

Width of Riparian and Upland Habitats Along Streams Occupied by 
Mountain Yellow-Legged Frog

    We estimated the width of riparian and upland habitats occupied by 
adults based on a study of movement ecology of mountain yellow-legged 
frogs in the Sierra Nevada Mountains (Pope and Matthews 2001). The 
study, in which a total of 581 adult frogs were marked, included 5 
stream segments and 11 lakes and ponds. The movement of mountain 
yellow-legged frogs throughout the entire annual period of activity 
(mid-late July to mid-late October) was recorded over two successive 
seasons (1997 and 1998). Of these marked frogs, 82 frogs made overland 
movements between water bodies that were not connected by aquatic 
pathways (straight line distance between lake 4 and lake 6 was 216 ft 
(66 m), straight line distance between lake 5 and stream 41 was 466 ft 
(142 m), and overland distance between lake 5 and unnamed lake was 
1,378 ft (420 m). Based on these results, 72 frogs traveled a minimum 
distance of 216 ft (66 m), 9 frogs traveled a minimum distance of 466 
ft (142 m), and 1 frog traveled 1,378 ft (420 m). The weighted mean 
overland distance traveled by mountain yellow-legged frogs was 
approximately 259 ft (79 m).
    We applied this weighted mean overland distance (rounded up to 262 
ft (80 m)) to determine the width of the riparian and upland habitats 
along streams occupied by the mountain yellow-legged frog in southern 
California. We also reviewed the preliminary results of an unpublished 
study that examined mountain yellow-legged frog movements in the Sierra 
Nevada Mountains (Knapp in litt. 2005). This study included 
observations of movement between Marmot Lake and Frog Lake (not 
connected by a stream) of at least 8,858 ft (2,700 m) by 3 frogs in 
2003 and 6 frogs in 2004. In comparison to Knapp's study, our 262 ft 
(80 m) width is a conservative estimate of the riparian and upland 
habitats occupied by the mountain yellow-legged frog.

Length of Streams Occupied by the Mountain Yellow-Legged Frog

    We estimated the length of stream occupied by mountain yellow-
legged frog adults (upstream and downstream distances from occurrences) 
based on review of several studies that give data on mountain yellow-
legged frog movements (Pope and Matthews 2001, Knapp in litt. 2005, 
Backlin et al. 2004, Vredenburg 2005). However, there are no definitive 
published studies on the upstream and downstream movements of mountain 
yellow-legged frog and we extracted portions of these studies that 
specifically identified stream movement. In their study of movement 
ecology of mountain yellow-legged frog, Pope and Matthews (2001) 
reported a tagged female that was recaptured in a lake 3,281 ft (1,000 
m) southeast of the study area, where a one-way trip requires a minimum 
of 1,968 ft (600 m) of travel in a fast-flowing stream. For streams in 
southern California, Backlin

[[Page 54113]]

et al. (2004) reported a range of distances between approximately 131 
ft (40 m) to 4,902 ft (1,494 m). In the Sierra Nevada Mountains, Knapp 
(in litt. 2005) reported dispersal along a stream that connects Marmot 
Lake and Cony Lake (a distance of approximately 2,953 ft (900 m)) by 12 
frogs in 2003 and 46 frogs in 2004. Knapp (in litt. 2005) also reported 
movement of 3 frogs in 2003 and 1 frog in 2004 of approximately 11,811 
ft (3,580 m) between Marmot Lake and No Good Lake that included both 
dispersal along a stream and overland movement. Finally, we received 
verbal information (Dr. V. Vredenburg, University of California-
Berkeley, pers. comm. 2005) that mountain yellow-legged frog tadpoles 
have been recovered approximately 5,905 ft (1,800 m) downstream from 
where they were tagged in the Sierra Nevada Mountains.
    Given the variability and sources of the available information on 
stream dispersal distances for mountain yellow-legged frogs, we are 
unable to calculate or estimate an average stream dispersal distance. 
Instead, we have defaulted to use the observed distance of 4,905 ft 
(1,495 m) that an adult mountain yellow-legged frog moved along City 
Creek, East Fork in the San Bernardino Mountains. While this 
observation represents the longest dispersal distance reported by 
Backlin et al. (2004) for the southern California, it is less than half 
the longest dispersal distance observed thus far in the Sierra Nevada 
Mountains (3,580 m; Knapp in litt. 2005). We believe the observation 
from City Creek represents the best available information to define 
occupied upstream and downstream reaches for the following reasons: (1) 
This dispersal distance connects known occurrences that occur along a 
stream or in populations that occur in tributaries; (2) this dispersal 
distance is specific to and representative of the southern California 
populations of the mountain yellow-legged frog; (3) movement distances 
between 131 ft (40 m) to 4,902 ft (1,494 m) that were identified by 
Backlin et al. (2004) represent home range movements and reflect the 
high site fidelity displayed by mountain yellow-legged frog and are 
therefore not representative of dispersal patterns (Backlin et al. 
2004); and 4) this distance is less than the maximum dispersal 
distances for stream and overland movements identified by Knapp (in 
litt. 2005; maximum distance was 3,580 m) for adults and by Vredenburg 
(pers. comm. 2005; maximum distance was 1,800 m) for tadpoles, and 
likely represents a conservative estimate of the upstream and 
downstream habitat occupied by the mountain yellow-legged frog in 
southern California.
    We are also proposing to designate critical habitat on lands that 
were historically occupied by the mountain yellow-legged frog, but are 
not known to be currently occupied. These subunits were all occupied 
within the past 45 years, contain features essential to the 
conservation of the species, and are considered essential for the 
conservation of the southern California DPS of the mountain yellow-
legged frog. These additional sites were selected based in part on 
comments and information given by herpetologists and experts on the 
southern California DPS of the mountain yellow-legged frog and by 
biologists from various management agencies (USGS, CDFG, USFS), who 
provided their knowledge of the area in terms of anthropogenic activity 
level, current habitat suitability for the species (survey data), and 
management potential. At this time, based on the best available 
information, we have determined that without these unoccupied areas 
managed and protected for the mountain yellow-legged frog, conservation 
of the species will not be possible in the foreseeable future.
    The criteria used for selecting the additional sites were the 
following:
    (1) Streams where the habitat contains the necessary PCEs (e.g., 
characteristics such as perennial water flow, pools, riffles, runs, 
riparian and upland habitat, banks with rocks or substrate);
    (2) Streams where the habitat has been characterized as 
``suitable'' for mountain yellow-legged frog by USGS, CDFG and USFS in 
their survey reports (i.e., contains habitat which meets additional, 
more specific characteristics that allow for a range of the species' 
biological needs, such as containing sites for breeding, feeding, 
sheltering, and other essential mountain yellow-legged frog behavioral 
patterns);
    (3) Streams that were known to be occupied by the species within 
the past 50 years, and where the habitat has not changed appreciably 
during that time (thus allowing for the assumption that previous 
occupancy still provides good indication of the known suitability of 
the site for the species' biological needs);
    (4) Streams that have potential for current occupancy by mountain 
yellow-legged frog (i.e., no conclusive evidence is available that the 
species is currently completely absent from the site due to few, 
incomplete, or no surveys having been conducted there recently, and the 
habitat has not changed appreciably);
    (5) Streams that are in remote locations (i.e., geographically 
distant from areas with heavy anthropogenic activities, such as 
vehicular traffic, human recreation, dredging, trout stocking, water 
regulation, pollution);
    (6) Streams that are not currently stocked with non-native aquatic 
species;
    (7) Streams where threats to the species either no longer exist, or 
are few and could be easily alleviated (e.g., by shifting current human 
recreational use patterns, and/or by trout removal) through voluntary 
cooperative conservation measures;
    (8) Streams where there is significant potential for re-occupation 
by the species, either by natural means through dispersal from 
currently occupied sites (i.e., located within 5 km of a currently 
occupied site), or by future re-introduction efforts.

Special Management Considerations or Protections

    As we undertake the process of designating critical habitat for a 
species, we first evaluate lands defined by those physical and 
biological features essential to the conservation of the species 
pursuant to section 3(5)(A) of the Act. Secondly, we evaluate lands 
defined by those features to assess whether they may require special 
management considerations or protection. Threats to those features that 
define important habitat (primary constituent elements) for the 
mountain yellow-legged frog include the direct and indirect impacts of 
some human recreation activities, and watershed management practices, 
water diversions from streams, fire management practices, and hazardous 
materials spills along roadways adjacent to streams.
    Recreational activities (e.g. camping, hiking, fishing, and 
recreational mining) are cited as factors that may have contributed to 
the decline of mountain yellow-legged frog in the San Gabriel, San 
Bernardino, and San Jacinto mountains (USFS 2002). In areas occupied by 
frogs, human use in and along streams can disrupt the lives of eggs, 
larvae, and adult frogs (Jennings 1995), and change the character of 
the stream (e.g., sediment and water quality), its bank and associated 
vegetation in ways that make sections of the stream less suitable as 
habitat for frogs. For example, logging activity, recreational mining, 
or heavy trampling may alter and/or decrease the presence of habitat 
structure within a stream such as bank overhangs, downed logs or 
branches, and rocks or may alter pool substrate, thereby reducing or 
eliminating available foraging, resting, breeding or egg-laying sites, 
and increasing suspended sediments and turbidity (PCE 1). 
Human activities

[[Page 54114]]

associated with heavy recreational use could also erode or denude 
stream banks or shores, reduce the extent of riparian vegetation, 
potentially reduce the available prey base for frogs, alter the amount 
of stream shade, and increase sedimentation within stream channels due 
to exposed soils, and impact water quality (e.g. temperature, pH) (PCEs 
1 and 2). Changes due to human recreation could contribute to 
adverse changes to the habitat that result in local extinctions where 
these activities occur in close proximity to mountain yellow-legged 
frog populations (Jennings 1995, Backlin et al. 2001). Heavy 
recreational use is specifically cited as a potential threat in the 
area of Bear Gulch and Vincent Gulch, the San Gabriel River--East Fork, 
Little Rock Creek, Fuller Mill Creek, and Dark Canyon and recreational 
mining is cited as a potential threat in the East Fork San Gabriel 
(Jennings 1994, 1995, 1998, 1999, USFS 2002). However, due to the 
proximity of the San Bernardino, San Gabriel and San Jacinto mountains 
to large urban centers and resulting high recreational use of these 
areas, there is potential for recreational impacts to all of the areas 
being proposed as critical habitat.
    Watershed management activities such as forest thinning or clearing 
for public safety or fire prevention (e.g., fuel load management) may 
also impact the physical and biological features determined to be 
essential for conservation of the species. Depending on the extent of 
alteration and the proximity to streams, forest thinning or clearing 
may alter streambed and riparian characteristics in ways that make 
sections of the stream less suitable as habitat for frogs. For example, 
thinning or clearing adjacent to streams could increase flooding and 
sedimentation within stream channels (Jennings 1998) due to exposed 
soils, impacting water quality (e.g. turbidity and pH (PCEs 
1). Alterations to riparian vegetation could reduce the prey-
base available for mountain yellow-legged frogs (PCE 2). At 
the same time, the presence of unnaturally high canopy cover or dense 
riparian vegetation could decrease the amount of basking areas 
available (PCE 2) and render the habitat unsuitable for 
mountain yellow-legged frog. Water diversion, such as water removal 
from the drainage system occupied by the species could reduce water 
levels and decrease the quality and extent of suitable breeding, 
wintering and foraging sites, and reduce the prey-base availability. 
The use of herbicides or other fire retardant chemicals to reduce fuel 
loads may impact water quality if used upslope or above a stream (PCE 
1). Hazardous material spills along roads that cross streams 
are also a potential threat impacting water quality (PCE 1). 
Little Rock Creek, East Fork City Creek, Dark Canyon, Fuller Mill and 
Hall Canyon are cited as having potentially high canopy cover and/or 
dense riparian vegetation within the watershed and having potential for 
a hazardous material spills due to an adjacent roadway (USFS 2002).
    The USFS prepared the Mountain Yellow-Legged Frog Conservation 
Assessment and Strategy: Angeles and San Bernardino National Forests 
(Strategy) (USFS 2002). This Strategy provides a framework for 
conservation actions to assist in the recover and conservation of the 
mountain yellow-legged frog and identifies the following management 
actions necessary to reduce impacts to mountain yellow-legged frog 
habitat from (1) recreation: Closing, rerouting or reconstructing 
unauthorized trails; closing parking areas used for unauthorized trail 
access; removing campsites and picnic tables adjacent to occupied 
creeks; installing signing at trailheads and along access points to 
promote understanding of the species' biology and habitat requirements; 
(2) high fuel loads: Developing plans for fuels reductions in the 
watershed which will examine potential riparian treatment of high 
canopy or dense vegetation; and (3) hazardous materials spills: 
developing an action plan for prevention, notification, and containment 
of spills before they enter the stream or its tributaries.
    Some of the conservation actions outlined in the Strategy have been 
implemented. For exampl