Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Astragalus ampullarioides (Shivwits milk-vetch) and Astragalus holmgreniorum (Holmgren milk-vetch), 77972-78012 [06-9794]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 71, Number 248 (Wednesday, December 27, 2006)]
[Rules and Regulations]
[Pages 77972-78012]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-9794]



[[Page 77971]]

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Part III





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; Designation of Critical 
Habitat for Astragalus ampullarioides (Shivwits milk-vetch) and 
Astragalus holmgreniorum (Holmgren milk-vetch); Final Rule

Federal Register / Vol. 71, No. 248 / Wednesday, December 27, 2006 / 
Rules and Regulations

[[Page 77972]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AU45


Endangered and Threatened Wildlife and Plants; Designation of 
Critical Habitat for Astragalus ampullarioides (Shivwits milk-vetch) 
and Astragalus holmgreniorum (Holmgren milk-vetch)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are 
designating critical habitat for two endangered plants, Astragalus 
ampullarioides (Shivwits milk-vetch) and Astragalus holmgreniorum 
(Holmgren milk-vetch) under the Endangered Species Act of 1973, as 
amended (Act). In total, approximately 6,289 acres (ac) (2,545 hectares 
(ha)) fall within the boundaries of the critical habitat designation 
for A. holmgreniorum in Mohave County, Arizona, and Washington County, 
Utah, and approximately 2,181 ac (883 ha) fall within the boundaries of 
the critical habitat designation for A. ampullarioides in Washington 
County, Utah.

DATES: This rule becomes effective on January 26, 2007.

ADDRESSES: Comments and materials received, as well as supporting 
documentation used in the preparation of this final rule, are available 
for public inspection, by appointment, during normal business hours, at 
the Utah Fish and Wildlife Office, 2369 West Orton Circle, Suite 50, 
West Valley City, Utah 84119 (801-975-3330). The final rule, economic 
analysis, and map are also available via the Internet at https://mountain-prairie.fws.gov/species/plants/milkvetche/index.htm.

FOR FURTHER INFORMATION CONTACT: Larry Crist, Field Supervisor, Utah 
Fish and Wildlife Office (see ADDRESSES), telephone 801-975-3330.

SUPPLEMENTARY INFORMATION:

Role of Critical Habitat in Actual Practice of Administering and 
Implementing the Endangered Species Act (16 U.S.C. 1531 et seq.)

    Attention to and protection of habitat is paramount to successful 
conservation actions. However, the role that designation of critical 
habitat plays in protecting habitat of listed species is often 
misunderstood. As discussed in more detail below in the discussion of 
exclusions under section 4(b)(2) of the Act, there are significant 
limitations on the regulatory effect of critical habitat designation 
under section 7(a)(2) of the Act. In brief, (1) Designation provides 
additional protection to habitat only where there is a Federal nexus; 
(2) the protection is relevant only when, in the absence of 
designation, destruction or adverse modification of the critical 
habitat would in fact take place (in other words, other statutory or 
regulatory protections, policies, or other factors relevant to agency 
decision-making would not prevent destruction or adverse modification); 
and (3) designation of critical habitat triggers the prohibition of 
destruction or adverse modification of that habitat, but it does not 
require specific actions to restore or improve habitat.
    Currently, only 475 species, or 36 percent of the 1,310 listed 
species in the United States under the jurisdiction of the Service, 
have designated critical habitat. We address the habitat needs of all 
1,310 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, the section 10 incidental take permit process, 
and cooperative, nonregulatory efforts with private landowners. The 
Service believes that it is these measures that may make the difference 
between extinction and survival for many species.
    In considering exclusions of areas originally proposed for 
designation, we evaluated the benefits of designation in light of 
Gifford Pinchot Task Force v. U.S. Fish and Wildlife Service. In that 
case, the Ninth Circuit 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 
considered in making section 7 adverse modification determinations. 
This critical habitat designation does not use the invalidated 
regulation in our consideration of the benefits of including areas in 
this final designation. The Service will carefully manage future 
consultations that analyze impacts to designated critical habitat, 
particularly those that appear to be resulting in an adverse 
modification determination. Such consultations will be reviewed by the 
Regional Office prior to finalizing to ensure that an adequate analysis 
has been conducted that is informed by the Director's guidance.
    On the other hand, to the extent that designation of critical 
habitat provides protection, that protection can come at significant 
social and economic cost. In addition, the mere administrative process 
of designating of critical habitat is expensive, time-consuming, and 
controversial. The current statutory framework of critical habitat, 
combined with past judicial interpretations of the statute, make 
critical habitat the subject of excessive litigation. As a result, 
critical habitat designations are driven by litigation and courts 
rather than biology, and made at a time and under a timeframe that 
limits our ability to obtain and evaluate the scientific and other 
information required to make the designation most meaningful.
    In light of these circumstances, 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.

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 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 limited ability to provide for 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, and is very 
expensive, thus diverting resources from conservation actions that may 
provide

[[Page 77973]]

relatively more benefit to imperiled 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) (42 U.S.C. 4321 et seq.). 
These costs, which are not required for many other conservation 
actions, directly reduce the funds available for direct and tangible 
conservation actions.

Background

    Our intent is to discuss only topics directly relevant to the 
designation of critical habitat in this final rule. For more 
information on Astragalus holmgreniorum and A. ampullarioides, refer to 
the final listing rule published in the Federal Register (66 FR 49560, 
September 28, 2001) and the proposed critical habitat rule published in 
the Federal Register (71 FR 15966, March 29, 2006).

Previous Federal Actions

    On March 29, 2006, we published a proposed rule to designate 
critical habitat for Astragalus holmgreniorum and A. ampullarioides (71 
FR 15966). The public comment period was open for 60 days until May 30, 
2006. On September 26, 2006, we published a revised proposed rule in 
the Federal Register, and issued a press release that announced the 
reopening of the public comment period on the proposed rule, and the 
availability of the draft economic analysis, draft environmental 
assessment, and revisions to proposed critical habitat boundaries for 
A. holmgreniorum and A. ampullarioides (71 FR 56085). The comment 
period was open for an additional 30 days until October 26, 2006.
    Concurrently, we have been working on the recovery plan for these 
two plant species. We published a notice of availability, and request 
for comments, for the draft recovery plan for Astragalus holmgreniorum 
and A. ampullarioides on August 1, 2006 (71 FR 57557). On September 29, 
2006, we announced the availability of the final recovery plan (71 FR 
57557).

Summary of Comments and Recommendations

    We requested written comments from the public on the proposed 
designation of critical habitat for Astragalus holmgreniorum and A. 
ampullarioides in the proposed rule published on March 29, 2006 (71 FR 
15966). We also contacted appropriate Federal, State, and local 
agencies; tribes; scientific organizations; and other interested 
parties and invited them to comment on the proposed rule.
    We received 17 written comments on the proposal published on March 
29, 2006 (71 FR 15966). These included responses from five peer 
reviewers, three Federal agencies, and nine organizations or 
individuals. During the comment period on the revised proposed rule (71 
FR 56085) that opened on September 26, 2006, and closed on October 26, 
2006, we received two comments pertaining to the revised proposed rule, 
draft economic analysis, draft environmental assessment, and revisions 
to proposed critical habitat boundaries. Including all comments 
received during both comment periods, 10 commenters supported the 
designation of critical habitat for Astragalus holmgreniorum and A. 
ampullarioides, and 1 opposed the designation. However, some of the 
supporting commenters disagreed with specific portions of the proposed 
designation, such as the acreage or delineation of individual critical 
habitat units. Eight letters included comments or information, but did 
not express support or opposition to the proposed critical habitat 
designation. Comments received were grouped into several general issues 
specifically relating to the proposed critical habitat designation for 
A. holmgreniorum and A. ampullarioides and are addressed in the 
following summary and incorporated into the final rule as appropriate. 
We did not receive any requests for a public hearing.

Peer Review

    In accordance with our policy published on July 1, 1994 (59 FR 
34270), we solicited independent opinions on the proposed critical 
habitat designation for Astragalus holmgreniorum and A. ampullarioides 
from eight knowledgeable individuals who have expertise with the 
species, the geographic region where the species occurs, and 
conservation biology principles. We received comments from five of the 
peer reviewers. The peer reviewers generally concurred with our methods 
and conclusions and provided additional information, clarifications, 
and suggestions to improve this final critical habitat designation.
    We reviewed all comments received from the peer reviewers and the 
public for substantive issues and new information regarding critical 
habitat, and associated draft economic analysis, for Astragalus 
holmgreniorum and A. ampullarioides. Substantive comments received have 
been addressed below, or incorporated into this final rule as 
appropriate.

Peer Review Comments

    Comment 1: One peer reviewer noted that the level of detail 
included in the rule for the two species was inconsistent, and that 
exotic species were not addressed for Astragalus holmgreniorum.
    Response: We examined the Background section of the proposed rule 
to designate critical habitat (71 FR 15966) and found that information 
was presented in equivalent amounts for both species, which included 
population size, structure, and habitat characteristics. However, 
information on exotic species associated with Astragalus holmgreniorum 
was inadvertently left out. Exotic species associated with Holmgren 
milk-vetch are Bromus rubens (red brome), Erodium cicutarium 
(storksbill), Malcomia africana (African mustard), and Bromus tectorum 
(cheatgrass) (Van Buren and Harper 2003a, p. 240). The threat of 
invasive weeds is addressed in the Special Management Considerations or 
Protections section of this rule.
    Comment 2: One peer reviewer (and several public commenters) 
questioned why we did not include the known occurrence of Astragalus 
holmgreniorum found north of Atkinville Wash and west of I-15, near the 
I-15 interchange with the proposed southern corridor, and presented 
information on the size and characteristics of the population that the 
peer reviewer thought supported its inclusion in critical habitat.
    Response: We did not include this area (which is north of the State 
Line Subunit 1a) because a natural wash separates it from other 
populations and much of the surrounding area, it lacks the Primary 
Constituent Elements (PCEs) due to differing soil type, and because of 
high human impacts due to concentrated off-road vehicle (ORV) use. 
Adjacent housing development to the west and south, and I-15 to the 
east, further compromise its ability to be self-sustaining. Critical 
habitat contributes to the overall conservation of listed species, but 
it is not the intent of the Act to designate critical habitat for every 
population or occurrence of a listed species. Critical habitat 
designations do not signal that habitat outside the designation is 
unimportant or may not contribute to recovery.
    Comment 3: One peer reviewer expressed concern that the proposed 
critical habitat did not adequately address ground-nesting pollinators 
and expressed an opinion that preserving

[[Page 77974]]

pollinator nesting sites, or areas where bees are known to nest, was 
important in the designation of critical habitat.
    Response: Our designation of critical habitat for Astragalus 
holmgreniorum and A. ampullarioides is based solely on their 
conservation needs. This rule does not designate critical habitat for 
pollinator species. However, pollinators are one of the PCEs necessary 
for the conservation of the two plant species, and the critical habitat 
unit boundaries were drawn to include sufficient acreage to accommodate 
habitat for pollinators. Thus, we expect the designation to afford 
protection to ground-nesting pollinators in proximity to the A. 
holmgreniorum and A. ampullarioides populations included in this final 
designation. We include additional information on pollinators in the 
Special Management Considerations and Protections (Special Management) 
section of this rule.
    Comment 4: One peer reviewer inquired about the impact of cattle on 
ground-nesting bees.
    Response: We have no information in our files quantifying or 
qualifying the impact of cattle to ground-nesting bees. However, some 
aspects of livestock grazing, such as soil compaction and reduction of 
flowering vegetation, could be a concern for ground-nesting bees. These 
activities similarly may limit the full and natural development of 
Astragalus holmgreniorum and A. ampullarioides and were considered 
under the Special Management section of the proposed rule (71 FR 15974-
15976, March 29, 2006).
    Comment 5: One peer reviewer stated that the use of the National 
Vegetation Classification System (NVCS) does not sufficiently identify 
habitat types for Astragalus holmgreniorum.
    Response: The NVCS is a systematic approach to classifying a 
continuum of natural vegetation nationwide. We included this 
information in the proposed designation because it allows land managers 
to assess the appropriate vegetation layer for Astragalus holmgreniorum 
on a Geological Information System and eliminate areas where the 
species is unlikely to reside. However, we did not rely on this 
information to define PCEs.
    Comment 6: One peer reviewer stated that Subunit 1a includes lands 
that are not occupied or are of marginal quality for Astragalus 
holmgreniorum.
    Response: All lands proposed for critical habitat are occupied, 
including Subunit 1a. Lands within Subunit 1a contain the PCEs for 
Astragalus holmgreniorum, and the plants occur in a patchy distribution 
throughout the unit. Therefore, we are including the entire subunit in 
this final critical habitat designation, as directed under 50 CFR 
424.12(d).
    Comment 7: One peer reviewer disagreed with the statement 
pertaining to Unit 1a that the I-15 right-of-way may allow pollinator 
flow between sites situated west and east of the highway, and pointed 
out that, although pollinators may travel between sites west and east 
of I-15, it seems likely that collisions with vehicles may be a serious 
drain on pollinator resources. The peer reviewer asked us to contact 
Dr. Tepedino, a bee biologist, about the ability of pollinators to 
successfully navigate I-15.
    Response: Although pollinators are likely to be killed by vehicles, 
neither we nor bee biologist Dr. Tepedino are aware of any information 
or ability to quantify pollinator mortality from vehicle collisions, 
except that mortality is likely to increase with the velocity of the 
vehicles.
    Comment 8: One peer reviewer recommended that we reduce the size of 
the Zion National Park Unit (Unit 5 for Astragalus ampullarioides) to 
only include the immediate area bordering the Chinle Trail at the south 
end of the occurrence where horses and hikers may trample plants and 
create erosion, because other areas within the unit were not subject to 
threats.
    Response: When determining which areas to include as critical 
habitat, we consider habitats that include the physical and biological 
features essential to the conservation of the species and that require 
special management considerations or protection. We have determined 
that the north end of the Zion Unit requires protection from many of 
the types of impacts that are affecting the south end of the unit, such 
as invasive nonnative weeds (71 FR 15980-15981, March 29, 2006).
    Comment 9: One peer reviewer responded to our request for comments 
concerning the inclusion of occupied habitat for the milk-vetches found 
in intervening areas of I-15 (i.e., between the northbound and 
southbound lanes, and within the highway right-of-way but outside the 
highway prism). The peer reviewer stated that the inclusion of occupied 
sites for Astragalus ampullarioides within the I-15 median is valuable 
because they are a significant part of the population, they are 
healthy, and management would not interfere with established protocols 
for highway management.
    Response: We included the I-15 site identified by the peer reviewer 
in this final designation. Also, in the Criteria to Identify Critical 
Habitat section, we provide additional information on the areas 
included in the designation to guide highway management.
    Comment 10: One peer reviewer stated that protecting and preserving 
habitat on private and State lands enhances property values.
    Response: We are unable to confirm that critical habitat 
designation enhances property values on private and State land, but we 
do know that property values have been enhanced adjacent to other open 
space in the county, e.g., Red Cliffs Desert Reserve. Our critical 
habitat designation is based solely on the provisions of section 4 of 
the Act; neither enhancing property values nor protecting open space is 
a basis for designating critical habitat.
    Comment 11: One peer reviewer suggested that we increase the size 
of our critical habitat units to create a buffer from the effects of 
development on adjacent lands and recreational use of these areas.
    Response: We share the concern about the effects of development and 
unregulated recreational use on critical habitat and addressed both 
impacts in the Special Management section of the proposed rule (71 FR 
15974-15976, March 24, 2006). We are designating the critical habitat 
units at a scale to maintain the populations and primary constituent 
elements essential to the conservation of the species per section 
3(5)(A) of the Act and regulations at 50 CFR 424.12.
    Comment 12: One peer reviewer stated that future management of the 
habitat currently administered by Arizona and Utah State Lands 
Departments will be critical for the survival of Astragalus 
holmgreniorum.
    Response: All lands included in the critical habitat designation 
are important to the conservation of Astragalus holmgreniorum and A. 
ampullarioides.
    Comment 13: One peer reviewer questioned how Subunit 2b for 
Astragalus holmgreniorum will be conserved under section 7 of the Act 
given the statement in the proposed rule that the Bureau of Land 
Management (BLM) is currently working with Santa Clara City to sell 
this land for development purposes.
    Response: Under section 7(a)(2) of the Act, all Federal agencies 
are required to ensure that any action they fund, authorize, or carry 
out is not likely to destroy or adversely modify critical habitat. 
Thus, BLM must ensure that its actions do not adversely modify or 
destroy critical habitat contained in Subunit 2b. The key factor 
related to the adverse modification determination is whether, with 
implementation of the

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proposed Federal action, the affected critical habitat would remain 
functional (or retain the current ability for the PCEs to function) to 
serve the intended conservation role for the species (Jones 2004). We 
understand that BLM is working on alternatives for retaining ownership 
of the South Hills population of Astragalus holmgreniorum (Douglas 
2006).
    Comment 14: In response to our statement, on pages 15968 and 15970 
of the proposed rule, that ``species may move from one area to another 
over time,'' one peer reviewer noted that known populations of 
Astragalus holmgreniorum occur in the same locations observed decades 
ago. Movements are more accurately described as a shift in population 
density in areas where suitable habitat occurs. In regard to A. 
holmgreniorum, if there are no major changes in hydrological patterns, 
one would not expect much movement of the population.
    Response: Populations of Astragalus holmgreniorum are being 
monitored in the same areas where they were observed decades ago, and 
this information is considered in this final rule. Although the 
establishment of new occupied areas may be rare, and the migration of 
seeds is likely to be localized, a new and independent establishment 
could result from arrival of a single seed (Epling and Lewis 1952, p. 
264).

Public Comments

    We received 12 public comments in response to our request for 
additional information in the proposed designation of critical habitat 
for Astragalus holmgreniorum and A. ampullarioides (71 FR 15966, March 
29, 2006). Responses that contained new, updated, or additional 
information were considered in this final rule. We consolidated the 
comments into several categories. Some public comments were addressed 
in the previous section's peer reviewer comments.

Comments Related to Adequacy of Units Proposed

    Comment 15: One commenter stated that the critical habitat 
designation is inadequate because it is only established where the 
plants currently exist. Suitable habitat encompasses the larger 
landscape. The critical habitat designation fails in its purpose of 
facilitating recovery because it does not protect this larger area or 
provide connectivity between populations.
    Response: Critical habitat contributes to the overall conservation 
of listed species, but it is not the intent of the Act to designate 
critical habitat for every population or occurrence of a listed 
species. In the Criteria Used to Identify Critical Habitat section of 
the proposed and final critical habitat rules, we describe the 
parameters used for delineating areas that contain the physical and 
biological features essential to the conservation of Astragalus 
holmgreniorum and A. ampullarioides, as required by the definition of 
critical habitat when considering areas occupied at the time of 
listing. We recognize that surveys to confirm the presence of A. 
holmgreniorum and A. ampullarioides populations have not occurred 
everywhere throughout the species' range. However, we determined that 
occupied areas containing the features essential to the conservation of 
these species support the majority of known locations (see the Criteria 
Used to Identify Critical Habitat section below). As a result of our 
methods, we found that the additional areas suggested by commenters 
were not essential to the conservation of A. holmgreniorum and A. 
ampullarioides.
    We also considered landscape issues when designing units to provide 
continuous habitat for reproduction, germination, seed dispersal, and 
pollination. Many units or subunits were designated by combining known 
occurrences and providing connectivity.
    Comment 16: One commenter noted that designating critical habitat 
that is separate, isolated, and fragmented will foment the eventual 
extinction of these populations.
    Response: The best available scientific information (71 FR 15966, 
March 29, 2006) does not support this concern. We have designated 
critical habitat for Astragalus holmgreniorum and A. ampullarioides in 
accordance with the Act. We have determined that the areas included in 
the designation are essential to the conservation of the two species. 
Many natural features separating the units, such as watersheds, land 
formations, and soil types, are unable to support the species.

Comments on Size and Areas To Be Included or Excluded

    Comment 17: Several commenters recommended that units that were 
close to each other be combined to provide connectivity for gene flow. 
Others provided reasons for designating larger areas, such as edge 
effects, current fragmentation, anticipated future fragmentation, 
chemical herbicide use, range of pollinator flights, invasive species, 
ORV trails, and recreational use. One commenter suggested that 
additional critical habitat for Astragalus holmgreniorum should be 
provided in Arizona to help offset all of the impacts that are 
occurring in Utah.
    Response: In delineating critical habitat, we considered hydrology 
for seed dispersal, soils for suitable habitat, elevation changes, and 
relief to determine range and amount of suitable habitat. We also 
considered existing natural and human-caused barriers to dispersal. As 
indicated in the process described in the proposal (also see Criteria 
Used to Identify Critical Habitat below), we have defined milk-vetch 
recovery populations in a manner that is consistent with the Act and 
our regulations at 50 CFR 424.12. The milk-vetch populations may appear 
close together on the maps, but in most cases known sites are separated 
by 1 mile (mi) (1.6 kilometers (km)) or more, which greatly decreases 
the expectation of frequent inter-site pollination. Critical habitat is 
designated in both Arizona and Utah due to occupied habitat containing 
the appropriate PCEs.
    Comment 18: Several commenters supported intervening lands of I-15 
being designated for Astragalus holmgreniorum and A. ampullarioides.
    Response: Intervening lands of I-15 are designated in this final 
rule. Additional information was incorporated into the Criteria to 
Identify Critical Habitat section below.
    Comment 19: One commenter recommended that we adjust the western 
boundary of Unit 1 for Astragalus ampullarioides to eliminate the 
inclusion of an existing mining operation.
    Response: The mining operation is outside both the proposed and 
final critical habitat boundaries.
    Comment 20: One commenter recommended that we adjust the southeast 
corner of Unit 4a for Astragalus ampullarioides to include only the 
west side of Harrisburg Ridge, because the east side is not part of the 
watershed.
    Response: We did not exclude the east side of Harrisburg Ridge. The 
critical habitat designation includes areas outside the watershed that 
are necessary (e.g., they provide adequate supply of pollinators) to 
support the reproductive success of Astragalus ampullarioides.
    Comment 21: BLM recommended an adjustment of Astragalus 
holmgreniorum Units 2a (Stucki Springs), and 2b (South Hills) to better 
reflect occurrence and habitat based on 2006 surveys.
    Response: We announced these proposed changes in our revised 
proposed rule and requested public comment on them (71 FR 56085,

[[Page 77976]]

September 26, 2006). The changes are incorporated into this final rule.
    Comment 22: One commenter recommended that we remove private lands 
or isolated Federal lands from Astragalus holmgreniorum Subunit 2b and 
Unit 3, and A. ampullarioides Unit 3, in order to designate only areas 
of private and State lands that have some potential to transfer to BLM 
ownership, or some other means of preservation. Another commenter 
expressed that land ownership should not be a consideration of 
determining critical habitat, and included a rationale based on lack of 
economic impacts on private lands.
    Response: All the lands proposed for critical habitat contain the 
features essential for the conservation of Astragalus holmgreniorum and 
A. ampullarioides regardless of ownership. In our final designation, we 
considered economic factors for both public and private lands. We 
determined that economic costs did not outweigh the benefits of 
designation for any of the proposed lands. However, we did exclude 
lands of the Shivwits Band of Paiute Indians (Tribe) based on a 
conservation agreement with the Tribe (see the Relationship of Critical 
Habitat to Tribal Lands section below).

Comments Providing Recommendations on Pollinators

    Comment 23: One commenter recommended larger unit sizes to conserve 
the most effective pollinators, which the commenter stated are the 
medium- to large-sized pollinators.
    Response: Our goal for the critical habitat designation is to 
include sufficient pollinator habitat and sufficient pollinator 
populations for the reproduction of Astragalus holmgreniorum and A. 
ampullarioides. We based our minimum unit size on the typical homing 
distance of the smallest pollinators 1,312 feet (ft) (400 meters (m)). 
A radius of 1,312 ft (400 m) encompasses 124 ac (50 ha), and ensures 
that pollinators have sufficient land to establish nesting sites, 
access floral resources, and provide pollinating services. We expect 
that the designated critical habitat units will provide a species-rich 
bee community for small, medium, and large pollinators. We find no 
supporting information indicating that a larger area is likely to 
improve pollinator services, because smaller pollinators are unlikely 
to travel much farther, and many medium and large pollinators can 
easily cover this distance.
    Comment 24: In the judgment of one commenter, adequate pollinator 
habitat exists adjacent to Unit 3 for Astragalus ampullarioides because 
areas of native vegetation remain within the Coral Canyon Development.
    Response: A golf course containing approximately 80 ac (32 ha) of 
grass turf interspersed with natural rock outcroppings exists to the 
west of Unit 3. This area is not sufficient to provide pollinator 
resources for the unit because the habitat does not contain a diverse 
natural flora capable of supporting an abundant pollinator population.

Comments Related to Tribal Issues

    Comment 25: One commenter stated that Astragalus ampullarioides 
occurrences found on land under the sovereignty of the Tribe should be 
protected and managed by the Tribe without Federal designation of 
critical habitat.
    Response: We agree that the Tribe is most able to manage and 
protect Astragalus ampullarioides on their lands that are held in trust 
by the United States. Fish, wildlife, and other natural resources on 
Tribal lands are better managed under Tribal authorities, policies, and 
programs than through Federal regulation wherever possible and 
practicable. We worked with Tribal leadership to create a sound 
management plan. On September 18, 2006, Tribal Chairman Glenn Rogers 
signed the Shivwits Band of Paiutes Management Plan for Astragalus 
ampullarioides. This management plan provides greater protection than 
critical habitat designation could provide. Therefore, this unit was 
excluded from final critical habitat (see the Government-to-Government 
Relationship with Tribes and 4(b)(2) Exclusions sections below).
    Comment 26: One commenter indicated that we should provide an 
environmental assessment and economic impact analysis on the proposed 
designation of critical habitat on Tribal lands.
    Response: We announced the availability of the draft economic 
analysis and draft environmental assessment for the proposed 
designation of critical habitat in the Federal Register (71 FR 56085, 
September 26, 2006) that included a description of the environmental 
and economic impacts of the designation on Tribal lands.
    Comment 27: One commenter indicated that Units 1 and 2, containing 
lands managed by BLM and the Tribe, should be combined into one larger 
unit because they are reasonably close.
    Response: Unit 2 is on Tribal land managed by the Tribe, who now 
have a management plan to ensure that the conservation of Astragalus 
ampullarioides can be achieved without the designation of critical 
habitat on Tribal lands. We are excluding Unit 2 from the final 
critical habitat designation (see the 4(b)(2) Exclusions section 
below).

Comments Providing Additional Scientific Information

    Comment 28: The U.S. Geological Survey (USGS) indicated that their 
recent research on Astragalus ampullarioides occupancy determined that 
the species also is affiliated with the Dinosaur Canyon Member of the 
Moenave, but could not confirm an affiliation with the Shinarump Member 
of the Chinle. All locations contain clay-rich soil.
    Response: We have included this information into this final rule.
    Comment 29: One commenter stated that new information concerning 
the preferred soils of Astragalus ampullarioides (described in comment 
29 above) expands the concept of potential habitat. The commenter 
suggested that new surveys beyond the geographic scope of currently 
known habitat are necessary and may have implications for the specific 
PCEs for A. ampullarioides.
    Response: We agree that the additional information on soils 
conducive to Astragalus ampullarioides survival will be useful for 
recognizing potential habitat and conducting surveys. However, we must 
base our critical habitat designation on the best available scientific 
data at the time of designation. Our final critical habitat designation 
is based on the protection of the features essential to the 
conservation of the known, existing populations of A. holmgreniorum and 
A. ampullarioides. We have incorporated this new information into the 
description of the PCEs (see Primary Constituent Elements section 
below).
    Comment 30: One commenter noted that herbivory is not mentioned in 
the discussion of PCEs for Astragalus ampullarioides despite its 
potential effects on reproductive output and long-term viability of the 
species, and the commenter provided information on reduction in fruit 
production by small mammals at one site.
    Response: Herbivory can impact Astragalus ampullarioides 
reproduction. The specific information provided by the commenter is 
considered in the Special Management section of this rule. However, we 
did not include a discussion on herbivory in our determination of the 
PCEs because herbivory is not relevant to our determination of the 
physical and biological features essential to the conservation of this 
species.

[[Page 77977]]

    Comment 31: One commenter noted that the proposed rule refers to 
``USGS soil descriptions,'' but that these descriptions were more 
likely produced by U.S. Department of Agriculture (USDA) Soil 
Conservation Service or USDA Natural Resources Conservation Service 
(NRCS).
    Response: In Washington County, Utah, the soil descriptions used 
originated in the Soil Survey of Washington County Utah (USDA Soil 
Conservation Service et al. 1977, pp. 7-10, 12-13, 20-22, 30-31, 34, 
44, 48, 124-129). In Mohave County, Arizona, information originated 
from Soil Survey of Shivwits Area, Arizona, Part of Mohave County (USDA 
NRCS et al. 2000, pp. 1-15, 65-68, 73-74, 113-114). This information is 
corrected in this final rule.
    Comment 32: One commenter indicated that the proposed rule 
discussed livestock grazing within Subunit 4b for Astragalus 
ampullarioides. However, livestock have been removed from this area.
    Response: We have updated our information.
    Comment 33: One commenter indicated that a population of Astragalus 
ampullarioides may exist to the south of Subunit 4b and should be 
surveyed to determine if it should be included in the critical habitat 
designation.
    Response: We have no further information regarding an area outside 
of Subunit 4b with existing Astragalus ampullarioides, and have made no 
boundary changes.
    Comment 34: One commenter noted that the proposed rule did not 
discuss that Unit 3 for Astragalus holmgreniorum is within a regional 
shooting range.
    Response: We have added this information to the final rule (see 
Critical Habitat Designation section).

Comments on Development, Recovery, and Other Issues

    Comment 35: One commenter thought that it may be too late to 
adequately protect the species because extensive development has 
occurred since listing.
    Response: We agree that the species is threatened by development. 
In addition to this critical habitat designation, the Act provides 
conservation mechanisms including the section 4 recovery planning 
process, section 6 funding to the States, section 7 consultations, and 
the section 9 protective prohibitions of unauthorized take and 
cooperative programs with private and public landholders and Tribes. A 
recovery plan was completed for these species on September 29, 2006 (71 
FR 57557).
    Comment 36: One commenter stated that various Federal, State, and 
local agencies and government representatives with roles in Washington 
County have been complicit in the demise of these plants. Priority is 
given to the desert tortoise and the protection of these lands at the 
expense of the plants.
    Response: We have no evidence supporting this comment. In many 
cases, such as within the recovery planning process for Astragalus 
holmgreniorum and A. ampullarioides, various Federal, State, and local 
agencies and government representatives with roles in Washington County 
are working together to protect lands containing rare plants, as well 
as other listed species, such as desert tortoise.
    Comment 37: One commenter stated that no viable plan exists to 
protect these species outside of the designated habitat.
    Response: We announced a final recovery plan for Astragalus 
holmgreniorum and A. ampullarioides (71 FR 57557, September 29, 2006). 
The recovery plan should result in protecting and enhancing current 
habitat; ensuring the habitat base for each recovery population is 
large enough to allow for natural population dynamics, population 
expansion where needed, the continued presence of pollinators, and 
sufficient connectivity to allow for gene flow within and among 
populations; achieving permanent land protection for at least four 
recovery populations of both A. holmgreniorum and A. ampullarioides; 
developing site-specific conservation agreements for all recovery 
populations and their habitat to protect the milk-vetches within 
existing State laws; prohibiting the use of pesticides or herbicides 
detrimental to either of the milk-vetches or their pollinators within 
the vicinity of all recovery populations; and collecting and storing 
seeds for all extant populations.
    Comment 38: One commenter stated that, although considerable study 
of the populations has taken place, no significant recovery actions 
have followed, and the recovery plans have not been implemented.
    Response: Both of these species were listed on September 28, 2001 
(71 FR 15966), and are in the early phases of the recovery process. On 
September 29, 2006, we announced a final recovery plan for Astragalus 
holmgreniorum and A. ampullarioides (71 FR 57557). Significant 
conservation efforts that are underway for A. holmgreniorum and A. 
ampullarioides are discussed on pages 37-40 of the recovery plan 
(Service 2006).
    Comment 39: One commenter stated that responsible Federal agencies 
and elected officials have failed to protect these species as required 
by the Act.
    Response: We are unaware of any failure under the Act to protect 
these species. No detailed information was provided by the commenter to 
support this claim.
    Comment 40: One commenter suggested that the critical habitat 
designation process could be improved by soliciting suggestions prior 
to publishing a proposal.
    Response: We have responsibility under the Act for designating 
critical habitat. An important facet of this responsibility is to 
provide opportunity for exchange of knowledge and participation. Two 
public comment periods were provided to facilitate communication, 
collect best available information, and address concerns of other 
agencies and stakeholders.
    Comment 41: One commenter suggested that the critical habitat 
designation process should be fully integrated with recovery plan 
preparation.
    Response: Our recovery plan for the milk-vetches (Service 2006) 
targets the same areas for recovery that we proposed for critical 
habitat. Special Management Considerations or Protections that are 
discussed within the proposed critical habitat rule (71 FR 15966, March 
29, 2006) address the same threats discussed in the recovery plan 
(Service 2006). We are working with other partners to address threats 
and population needs to reach recovery.
    Comment 42: The Washington County Growth and Conservation Act, as 
currently proposed by Senator Robert Bennett, may have serious 
implications for the future of the Astragalus holmgreniorum and A. 
ampullarioides.
    Response: Congressional activities are not evaluated in the 
designation of critical habitat, and, therefore, this comment is 
outside the scope of this designation.
    Comment 43: Many commented that our discussion of the value of 
designating critical habitat, and the procedural and resource 
difficulties involved, was inappropriate and should be addressed in a 
different forum, not in the news release for a critical habitat rule.
    Response: As discussed in the Designation of Critical Habitat 
Provides Little Additional Protection to Species, Role of Critical 
Habitat in Actual Practice of Administering and Implementing the Act, 
and Procedural and Resource Difficulties in Designating

[[Page 77978]]

Critical Habitat sections of this and other critical habitat 
designations, we believe that, in most cases, other conservation 
mechanisms provide greater incentives and conservation benefits than 
the designation of critical habitat. Other mechanisms include the 
section 4 recovery planning process, section 6 funding to the States, 
section 7 consultations, the section 9 protective prohibitions of 
unauthorized take, the section 10 incidental take permit process, and 
cooperative programs with private and public landholders and Tribal 
nations.
    Comment 44: No action has ever been taken to list the native bee, 
Peridita meconis, or determine its status.
    Response: This action is to designate critical habitat for 
Astragalus holmgreniorum and A. ampullarioides. The status of Peridita 
meconis is outside the scope of this action.

Comments Related to the Draft Economic Analysis

    Comment 45: Two commenters stated that the St. George area is one 
of the fastest growing metropolitan areas in the United States, and 
that its growth rate may increase. The commenters felt that, 
considering the rapid population growth, the critical habitat 
determination would provide open space relief and an economic amenity 
value. The commenters believe that the critical habitat determination 
may provide a future eco-tourism industry, and a ``population safety 
buffer'' benefit for the airport.
    Response: Section 4.1 of the Draft Economic Analysis acknowledged 
that Washington County is one of the fastest growing counties in the 
United States. However, section 4.1 also highlights that the County 
believes the population increase will not cause overcrowding because 
more than 75 percent of the land in the County is managed by the 
Federal government (i.e., BLM, U.S. Forest Service, and National Park 
Service) and is not expected to be developed. The Draft Economic 
Analysis does not forecast precluding development within the boundaries 
of the proposed critical habitat determination. Residential, 
commercial, and industrial development is expected to occur; thus the 
proposed critical habitat determination that occurs on non-Federal land 
is not expected to provide a ``population safety buffer'' benefit for 
the new regional airport located approximately 3 mi (4.8 km) east of 
Subunit 1c. No data are available to describe or forecast how many 
people currently visit the area to allow for the measurement of the 
impact of critical habitat determination on the future eco-tourism 
industry.
    Comment 46: One commenter thought that the draft economic analysis 
did not consider the effect of the new regional airport.
    Response: The proposed location of the new regional airport is 
approximately 3 mi (4.8 km) east of Subunit 1c for Astragalus 
holmgreniorum. While airport-related species conservation activities 
are not expected during construction and operation of the airport, the 
Draft Economic Analysis included consideration of the County growth 
forecast and general plan, which reflect the effects of a new regional 
airport; therefore, the economic analysis captures any economic impacts 
related to population growth resulting from the new regional airport.

Comments From States

    Comments were received from the Arizona State Land Department 
(ASLD), Arizona Department of Transportation, and Arizona Game and Fish 
regarding the proposal to designate critical habitat for the Astragalus 
holmgreniorum, and are addressed below.

Comments on Areas in the Median of Interstate-15

    Comment 47: One commenter pointed out that the proposed rule 
indicated that critical habitat would not include existing manmade 
structures (such as roads) that lack PCEs, or the land on which such 
structures are located. The commenter thought that manmade structures, 
such as cut slopes and fill slopes, as well as regularly graded areas 
along the I-15 right-of-way, should be excluded, or that areas of 
inclusion along I-15 should be better defined.
    Response: Where we have specific information on areas within the 
designation that do not contain the PCEs, we have not included them in 
the final rule (see Summary of Changes). The existence of manmade 
structures are excluded by text in the rule clarifying that these areas 
do not contain the PCEs and are not included as critical habitat (see 
Criteria to Identify Critical Habitat).
    Comment 48: The proposed rule states that the long-term 
conservation of Astragalus holmgreniorum and A. ampullarioides is, in 
part, dependent on the ability to keep critical habitat free from major 
ground-disturbing activities. While best management practices can and 
likely will be developed in coordination with the Service, it is 
unlikely that the I-15 right-of-way can be kept free from ground-
disturbing activities, such as road maintenance, vehicle collisions, or 
motorists pulling off the roadway.
    Response: The areas we are designating as critical habitat provide 
some or all of the habitat components essential for the conservation of 
Astragalus holmgreniorum and A. ampullarioides. Best management 
practices are likely to reduce ground-disturbing activities, and are 
evaluated during section 7 consultations on projects with a Federal 
nexus, e.g., actions related to the Federal Highway Administration.
    Comment 49: One commenter stated that designation of critical 
habitat within the I-15 right-of-way would not provide any additional 
benefits because projects typically receive funding from the Federal 
Highway Administration and are already subject to section 7 
consultation.
    Response: Jeopardy and adverse modification analyses differ under 
section 7 of the Act and may result in differing determinations 
depending on the specific action at issue. The jeopardy analysis 
usually addresses the survival and recovery needs of a species in a 
qualitative fashion. Generally, if a proposed Federal action is 
incompatible with the viability of a population(s) essential to 
recovery, a jeopardy finding is considered to be warranted because of 
the relationship of essential populations to the survival and recovery 
of the species as a whole. Adverse modification analyses are conducted 
using an analytical framework described in the Director's December 9, 
2004, memorandum. The key factor related to the adverse modification 
determination is whether, with implementation of the proposed Federal 
action, the affected critical habitat would remain functional (or 
retain the current ability for the PCEs to be functionally established) 
in serving the intended conservation role for the species. Activities 
that may destroy or adversely modify critical habitat also may 
jeopardize the continued existence of the species. Additionally, not 
all actions that occur in critical habitat will be subject to section 7 
of the Act, because they may not be Federal actions.
    Comment 50: The ASLD commented that Subunits 1a and 1b for 
Astragalus holmgreniorum, which are under its management, are slated 
for commercial and mixed residential uses. While they are not opposed 
to the designation, they have concerns regarding the development 
potential of the lands due to the designation.
    Our Response: All the lands proposed for critical habitat contain 
the features essential for the conservation of Astragalus holmgreniorum 
and A.

[[Page 77979]]

ampullarioides regardless of ownership. In our final designation, we 
considered economic factors for both public and private lands. We 
determined that economic costs did not outweigh the benefits of 
designation for any of the proposed lands. However, we did exclude 
Tribal lands based on a conservation agreement with the Tribe. Further, 
critical habitat designation for plants does not necessarily affect 
state or private lands, unless there is a Federal nexus, such as when 
Federal funds are involved.

Summary of Changes From Proposed Rule

    In developing the final critical habitat designation for Astragalus 
holmgreniorum and A. ampullarioides, we reviewed the comments received 
on our proposed rule, draft economic analysis, and draft environmental 
assessment, and conducted further evaluation of lands included in the 
proposal. Based on our review, we changed our proposed designation as 
follows:
    (1) We adjusted the critical habitat boundaries of Astragalus 
holmgreniorum Subunits 2a and 2b to better capture existing occupied 
habitat that contains the PCEs, based on biological information 
received during the public comment period. This resulted in the 
addition of 26 ac (9 ha) in Subunit 2a, and the loss of 18 ac (6 ha) in 
Subunit 2b (see the revised proposed rule published on September 26, 
2006, at 71 FR 56085).
    (2) We adjusted the boundaries of Subunits 1a and 1c for Astragalus 
holmgreniorum so that they do not contain areas without the PCEs or 
areas that do not meet the designation criteria (are essential to the 
continued conservation of the species and require special management 
consideration or protection). This resulted in the removal of 191 ac 
(78 ha) and 2 ac (1 ha) respectively.
    (3) Under section 4(b)(2) of the Act, we excluded Unit 2 for 
Astragalus ampullarioides. On September 18, 2006, Glenn Rogers, Band 
Chairman, signed the Shivwits Band of Paiutes Management Plan for A. 
ampullarioides. This management plan provides greater protection than 
critical habitat designation could provide. Because the management plan 
ensures that the conservation of A. ampullarioides can be achieved 
without the designation of critical habitat on Tribal lands, we are 
excluding Unit 2 from the final critical habitat designation (see 
4(b)(2) Exclusions section below). This exclusion amounts to a 
reduction of 240 ac (97 ha) in the total critical habitat designation 
for A. ampullarioides.
    (4) We modified the descriptions of the PCEs for clarity; however, 
the substance of the PCEs has not changed.

Critical Habitat

    Critical habitat is defined in section 3 of the Act as (i) The 
specific areas within the geographical 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 
geographical 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, as defined under section 3 of the Act, means 
to use and the use of all methods and procedures which are necessary to 
bring any endangered species or threatened species to the point at 
which the measures provided pursuant to the Act are no longer 
necessary. Such methods and procedures include, but are not limited to, 
all activities associated with scientific resources management such as 
research, census, law enforcement, habitat acquisition and maintenance, 
propagation, live trapping, and transplantation, and, in the 
extraordinary case where population pressures within a given ecosystem 
cannot be otherwise relieved, may include regulated taking.
    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. Section 7 is a 
purely protective measure and does not require implementation of 
restoration, recovery, or enhancement measures.
    To be included in a critical habitat designation, the habitat 
within the area occupied by the species 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 
data available, habitat areas that provide essential life cycle needs 
of the species (i.e., areas on which are found the 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 thereon may require special 
management or protection. Thus, we do not include areas where existing 
management is sufficient to conserve the species. (As discussed below, 
such areas also may be excluded from critical habitat pursuant to 
section 4(b)(2).) Accordingly, when the best available scientific data 
do not demonstrate that the conservation needs of the species require 
additional areas, we will not designate critical habitat in areas 
outside the geographical area occupied by the species at the time of 
listing. However, an area currently occupied by the species but was not 
known to be occupied at the time of listing will likely, but not 
always, be essential to the conservation of the species and, therefore, 
typically included in the critical habitat designation.
    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 data available. They require Service biologists to the 
extent consistent with the Act and with the use of the best scientific 
data available, to use primary and original sources of information as 
the basis for recommendations to designate critical habitat. When 
determining which areas are critical habitat, a primary source of 
information is generally the listing package 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

[[Page 77980]]

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. For these reasons, critical habitat 
designations do not signal that habitat outside the designation is 
unimportant or may not be required for recovery.
    Areas that support populations, but are outside the critical 
habitat designation, will continue to be subject to conservation 
actions implemented under section 7(a)(1) of the Act and to the 
regulatory protections afforded by the section 7(a)(2) jeopardy 
standard, as determined on the basis of the best available information 
at the time of the action. Federally funded or permitted 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 if new information 
available to these planning efforts calls for a different outcome.

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 designate as critical 
habitat, we consider physical and biological features (PCEs) that are 
essential to the conservation of the species, that are within areas 
occupied by the species at the time of listing, and that may require 
special management considerations and 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; and 
habitats that are protected from disturbance or are representative of 
the historic geographical and ecological distributions of a species.
    The specific PCEs required for Astragalus holmgreniorum and A. 
ampullarioides are derived from the biological needs of these milk-
vetches as described in the proposed critical habitat designation (71 
FR 15966; March 29, 2006).

Primary Constituent Elements for Astragalus holmgreniorum

    Based on our current knowledge of the life history, biology, and 
ecology of the species and the requirements of the habitat to sustain 
the essential life history functions of the species, the primary 
constituent elements for Astragalus holmgreniorum are:
    (1) Appropriate geological layers or soils that support individual 
Astragalus holmgreniorum plants. A. holmgreniorum is found on the 
Virgin Limestone member, middle red member, and upper red member of the 
Moenkopi Formation and the Petrified Forest member of the Chinle 
Formation (Harper and VanBuren 1997; Hughes 2005). Associated soils are 
defined by USDA et al. (1977 and 2000) as Badland; Badland, very steep; 
Eroded land-Shalet complex, warm; Hobog-rock land association; Isom 
cobbly sandy loam; Ruesh very gravelly fine sandy loam; Gypill Hobog 
complex, 6 to 35 percent slopes; Gypill very cobbly sandy loam, 15 to 
40 percent slopes; and Hobog-Grapevine complex, 2 to 35 percent slopes. 
These soils are generally found at elevations from 2,430 to 3,000 ft 
(756 to 914 m), support associated native plant species, and have a low 
presence or lack of Larrea tridentata (creosote bush).
    (2) Topographic features/relief (mesas, ridge remnants, alluvial 
fans, and fan terraces, their summits and backslopes, and gently 
rolling to steep swales) and the drainage areas along formation edges 
with little to moderate slope (0 to 20 percent).
    These topographic features/relief contribute to the soil substrate 
and vegetative community, natural weathering and erosion, and the 
natural surface and subsurface structure that provides minimally-
altered or unaltered hydrological conditions (e.g., seasonally 
available moisture from surface or subsurface runoff) on which 
Astragalus holmgreniorum depends.
    (3) The presence of insect visitors or pollinators, such as 
Anthophora captognatha, A. damnersi, A. porterae, Anthophora spp., 
Eucera quadricincta, Omia titus, and two types of Dialictus sp.

Primary Constituent Elements for Astragalus ampullarioides

    Based on our current knowledge of the life history, biology, and 
ecology of the species, the primary constituent elements for Astragalus 
ampullarioides are:
    (1) Outcroppings of soft clay soil, often purple-hued, within the 
Chinle Formation and the Dinosaur Canyon Member of the Moenave 
Formation, at elevations from 3,018 to 4,367 ft (920 to 1,330 m).
    Plant species that are characteristically found on these clay soils 
within the Chinle Formation and can indicate the presence of this PCE 
were included in the Background section of the proposed critical 
habitat designation (71 FR 15966; March 29, 2006).
    (2) Topographic features/relief, including alluvial fans and fan 
terraces, and gently rolling to steep swales, with little to moderate 
slope (3 to 24 percent), that are often markedly dissected by water 
flow pathways from seasonal precipitation.
    Associated topographic features/relief contribute to the soil 
substrate and vegetative community described above, nat