Federal Register: Part II [50 CFR Part 17]

DEPARTMENT OF THE INTERIOR

CFR Citation: 50 CFR Part 17

RIN ID: RIN 1018-AT42

NOTICE: Part II

DOCUMENT ACTION: Proposed rule.

SUBJECT CATEGORY: Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for the Arroyo Toad (Bufo californicus)

DATES: We will accept comments from all interested parties until May 28, 2004. We must receive requests for public hearings, in writing, at the address shown in the ADDRESSES section by May 13, 2004.

DOCUMENT SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to designate critical habitat for the federally endangered arroyo toad (Bufo californicus) pursuant to the Endangered Species Act of 1973, as amended (Act). We propose to designate a total of approximately 138,713 acres (ac) (56,133 hectares (ha)) of critical habitat in Monterey, Santa Barbara, Ventura, Los Angeles, San Bernardino, Riverside, Orange, and San Diego Counties, California.

We hereby solicit data and comments from the public on all aspects of this proposal, including data on economic and other impacts of designation. We may revise this proposal prior to final designation to incorporate or address new information received during the two public comment periods.

SUMMARY: Interior Department, Fish and Wildlife Service,

SUPPLEMENTAL INFORMATION

Designation of Critical Habitat Provides Little Additional Protection to Species

In 30 years of implementing the Endangered Species Act of 1973, as amended (Act) (16 U.S.C. 1531 et seq.), we have found that the designation of statutory critical habitat provides little additional protection to most listed species, while consuming significant amounts of available conservation resources. Our 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. We believe 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.
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 ESA can protect species with and without critical habitat designation, critical habitat designation may be redundant to the other consultation requirements of section 7.''

Currently, only 445 species or 36 percent of the 1,244 listed species in the U.S. under our jurisdiction have designated critical habitat. We address the habitat needs of all 1,244 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. We believe that it is these measures that may make the difference between extinction and survival for many species.
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 us to an everincreasing series of court orders and court approved settlement agreements, compliance with which now consumes nearly the entire listing program budget. This leaves us with little ability to prioritize our 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, and to comply with the growing number of adverse court orders. As a result, our own proposals to list critically imperiled species, and make final listing determinations on existing proposals, are all significantly delayed.

The accelerated schedules of courtordered designations have left us with almost no ability to provide for adequate public participation or to ensure a defectfree rulemaking process before making decisions on listing and critical habitat proposals due to the risks associated with noncompliance with judiciallyimposed 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.

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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 of 1969all are part of the cost of critical habitat designation. These costs result in minimal 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.

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) The reasons why any habitat should or should not be determined to be critical habitat as provided by section 4 of the Act, including whether the benefit of designation will outweigh any threats to the species due to designation;
(2) Specific information on the amount and distribution of arroyo toad habitat, and what habitat is essential to the
conservation of the species and why;
(3) Land use designations and current or planned activities in the areas proposed as critical habitat and their possible impacts on proposed critical habitat;
(4) Any foreseeable economic or other potential impacts resulting from the proposed designationin particular, any impacts on small entities;
(5) Economic and other values associated with designating critical habitat for the arroyo toad, such as those derived from nonconsumptive uses (e.g., hiking, camping, birdwatching, enhanced watershed protection, improved air quality, increased soil retention, ``existence values,'' and reductions in administrative costs); and
(6) 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 section). Please submit Internet comments to fw1artoch@r1.fws.gov in ASCII file format and avoid the use of special characters or any form of encryption. Please also include ``Attn: Arroyo toad'' in your email 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 Ventura Fish and Wildlife Office at phone number 805/6441766. Please note that the Internet address fw1artoch@r1.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. Individual respondents may request that we withhold their home address 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.

Public Hearings

The Act provides for one or more public hearings on this proposal, if requested. Requests for public hearings must be made, in writing, at least 15 days prior to the close of the public comment period. We will schedule public hearings on this proposal, if any are requested, and announce the dates, times, and places of those hearings in the Federal Register and local newspapers at least 15 days prior to the first hearing.

Background

Background information on the arroyo toad can be found in our final designation of critical habitat for this species, published on February 7, 2001 (66 FR 9414). That information is incorporated by reference into this proposed rule. The following new information has come to our attention since that time:
(1) Individual toads have been observed as far as 1.2 miles (mi) (2 kilometers (km)) from the streams where they breed (Service 1999; Varanus Biological Services, Inc., in litt. 1999), but are most commonly found within 650 to 3,280 feet (ft) (200 to 1,000 meters (m)) of those streams in coastal areas with broad floodplains (Griffin et al. 1999; Holland and Sisk 2000), and 160 to 650 ft (50 to 200 m) in more mountainous areas away from the coast (Ramirez 2002a, 2002b, 2002c, 2003). Arroyo toads typically burrow underground during periods of inactivity and thus tend to use upland habitats that have sandy, friable (readily crumbled) soils, but upland sites with extremely compact soils can also be used (D. Holland, in litt. 2000). (2) Juvenile arroyo toads remain on or near the saturated substrate at the edges of breeding pools from a week to several months after metamorphosis (D. Holland, in litt. 2000). They are active during the day and can be exposed on the barren sand, although they are rather cryptic (i.e., hidden or camouflaged) at this time. Crushing of toads by humans, livestock, or vehicles can be a substantial source of mortality at this stage (Service 1999; D. Holland, in litt. 2000). (3) In a study using pitfall traps, Holland and Sisk (2000) reported arroyo toad captures in upland habitats averaging more than 1,640 ft (500 m) and 980 ft (300 m) from two separate coastal streams; one arroyo toad was even captured 3,940 ft (1,175 m) beyond the edge of the riparian habitat bordering the stream. However, radio telemetry and pitfall trap studies from a variety of inland streams often bordered by steep, dry terrain show arroyo toad activity typically closer to the active stream channel. Four separate studies of inland populations by Ramirez (2002a, 2002b, 2002c, 2003) showed that arroyo toads burrowed no farther than 121 to 1,062 ft (37 to 324 m) from the edge of a stream, with an overall average of approximately 52 ft (16 m) between a toad's burrow and the edge of the stream.
(4) The nonnative organisms whose introduction and spread into arroyo toad habitat can pose a particularly serious threat include, among others, giant reed (Arundo donax), bullfrogs (Rana catesbeiana), green sunfish (Lepomis cyanellus), and chytrid fungus (Batrachochytrium dendrobatidis) (Sweet 1992; Service 1999; S. Sweet, pers. comm. 2003). (5) In addition to a variety of other human activities outlined in a previous Federal Register notice (66 FR 9414), offhighway vehicle use within stream channels, floodplains, and adjacent uplands and the inadvertent or intentional introduction of nonnative species may cause adverse impacts to arroyo toads.
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Previous Federal Actions

We designated a total of approximately 182,360 acres (ac) (73,780 hectares (ha)) of critical habitat for the arroyo toad on February 7, 2001 (66 FR 9414). On November 6, 2001, the Building Industry Legal Defense Foundation, Foothill/Eastern Transportation Corridor Agency, National Association of Home Builders, California Building Industry Association, and Building Industry Association of San Diego County filed a lawsuit in the District of Columbia against the Service challenging the designation of arroyo toad critical habitat and alleging errors by the Service in promulgating the final rule. Building Industry Legal Defense Foundation, et al. v. Gale Norton, Secretary of the Interior, et al. Civ. No. 012311 (JDB) (D.D.C.). On October 30, 2002, the court set aside the designation and ordered us to publish a new critical habitat designation final rule for the arroyo toad by July 30, 2004.

This proposal for critical habitat differs from the previous designation of critical habitat for the arroyo toad with respect to the mapping grid size and changes in locations of critical habitat due to new survey data. We reduced the minimum mapping unit from a 250meter UTM grid to a 100meter UTM grid. This allows for the grid to more closely follow watershed boundaries. Based on new survey results and reevaluation of arroyo toad habitat, additional stream reaches are included in this proposal, including sections of the Santa Clara River, Cajon Wash, Kitchen Creek, and Kinley Creek. The lengths of several streams included in proposed critical habitat are also reduced in several instances from the previous designation. These reductions occur where the likelihood of arroyo toad occupancy and the quality of arroyo toad habitat are low, such as along portions of Piru, San Francisquito, and Castaic Creeks. In addition, we have determined that habitat conditions in Arroyo Seco are not essential for the conservation of the species since closer scrutiny and comments from Forest Service biologists and USGS biologists indicate the stream gradient in Arroyo Seco is too steep for the arroyo toad. Consequently, we have not included this area in this proposal. New exclusions from critical habitat under section 4(b)(2) are contained in this proposed rule and discussed in the relevant exclusion sections.

Critical Habitat

Critical habitat is defined in section 3 of the Act. It receives protection under section 7 of the Act. Further information regarding the definition of critical habitat and how we implement related policies and regulations can be found in the Federal Register at 66 FR 9414.

Methods

Our methods for identifying the arroyo toad critical habitat included in this proposal are identical to the methods we used to make our final designation for this species on February 7, 2001 (66 FR 9414).

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 those physical and biological features (primary constituent elements) that are essential to the conservation of the species, and that may require special management considerations or protection. These features are used for all listed species and include, but are not limited to: Space for individual and population growth and for normal behavior; food, water, or other nutritional or physiological requirements; cover or shelter; sites for breeding, reproduction, and rearing of offspring; and habitats that are protected from disturbance or are representative of the historic and geographical and ecological distributions of a species.

The specific biological and physical features, otherwise referred to as the primary constituent elements (PCEs), which comprise essential arroyo toad habitat are described below. These lands provide aquatic and terrestrial habitat essential for the maintenance of self sustaining populations and metapopulations (a set of local populations or breeding sites within an area, where typically migration from one local population or breeding site to other areas containing suitable habitat is possible, but not routine) of arroyo toads throughout its range.
Space for Individual and Population Growth, and for Normal Behavior

The arroyo toad is found along mediumtolargesized streams in coastal and desert drainages in central and southern California and Baja, Mexico. It occupies aquatic, riparian (areas near a source of water), and upland habitats in a reduced number of suitable drainages within its range. Essential habitat for the arroyo toad is created and maintained by the fluctuating hydrological, geological, and ecological processes operating in riparian ecosystems and the adjacent uplands. Periodic flooding that modifies stream channels, redistributes channel sediments, and alters pool location and form, coupled with upper terrace stabilization by vegetation, is required to keep a stream segment suitable for all life stages of the arroyo toad. Periodic flooding helps maintain areas of open, sparsely vegetated, sandy stream channels and terraces.

Eggs and tadpoles require aquatic habitat, as described below. Juvenile and adult arroyo toads require and spend much of their lives in riparian and upland habitats adjacent to breeding locations. Riparian habitats used by subadults and adults for foraging and burrowing include sand bars, alluvial terraces, and streamside benches that lack vegetation, or are sparsely to moderately vegetated. Upland habitats used by arroyo toads during both the breeding and nonbreeding seasons include alluvial scrub, coastal sage scrub, chaparral (shrubby plants adapted to dry summers and moist winters), grassland, and oak woodland. Arroyo toads also have been found in agricultural fields (Griffin et al. 1999), but these lands may constitute sinks (areas where mortality rates are higher than reproduction rates) over the long term, due to tilling, pesticide and fertilizer applications, and heavy equipment use (Griffin and Case 2001).

The substrate in habitats preferred by arroyo toads consists primarily of sand, fine gravel, or pliable soil, with varying amounts of large gravel, cobble, and boulders. Areas that are damp and have less than 10 percent vegetation cover provide the best conditions for juvenile survival and rapid growth (Service 1999). Arroyo toads must be able to move between the stream and upland foraging sites, as well as up and down the stream corridor.

Food, Water, and Physiological Requirements

Arroyo toad tadpoles eat microscopic algae, bacteria, and protozoans sucked up from the spaces among pebbles, gravel, and sand or abraded from stones (Sweet 1992). Juveniles and adults feed on insects, but specialize on ants. When foraging, arroyo toads are often found around the driplines of oak trees. These areas often lack vegetation, yet have sufficient levels of prey. When active at night, toads often can be observed near ant trails feeding on ants, beetles, and other prey.

Cover or Shelter

During the day and other periods of inactivity, arroyo toads seek shelter by burrowing into the sand. Thus, areas of sandy or friable (readily crumbled) soils are necessary to burrow, but these soils can be interspersed with gravel or
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cobble deposits. Arroyo toads may also seek temporary shelter under rocks or debris and have been found in mammal burrows on occasion. Upland sites with extremely compact soils can also be used for foraging and dispersal (D. Holland, in litt. 2000).

Sites for Breeding, Reproduction and Rearing of Offspring

The arroyo toad has specialized breeding habitat requirements. They favor shallow pools and open sand and gravel channels along low gradient (typically less than 6 percent) reaches of mediumtolarge sized streams (Service 1999). These streams can have either intermittent or perennial streamflow and typically experience periodic flooding that scours vegetation and replenishes fine sediments. In at least some portions of its range, the species also breeds in smaller streams and canyons where lowgradient breeding sites are more sporadically distributed. Breeding pools must persist long enough for the completion of larval development (at least in most years), which is generally March through June, depending on location and weather. Sweet (1992) measured the average age to metamorphosis of arroyo toad larvae on the Los Padres National Forest at 71 days, with a predicted minimum of 62 days. Peak metamorphosis occurs during June and July in the northern part of the toad's range, and from late April through June further south, although it may be later, particularly at higher elevations (D. Holland, in litt. 2000).

Breeding arroyo toads lay their eggs in water over substrates of sand, gravel, or cobble in open sites such as overflow pools, old flood channels, and shallow pools along streams. Such habitats rarely have closed canopies over the lower banks of the stream channel due to periodic flood events. Heavily shaded pools are generally unsuitable for larval and juvenile arroyo toads because of lower water and soil temperatures and poor algal mat development. Pools less than 12 inches (30 centimeters (cm)) deep with clear water, flow rates less than 0.2 ft per second (5 cm per second), and bottoms composed of sand or well sorted fine gravel are favored by adults for breeding and egg deposition (Sweet 1992). Larvae usually hatch in 4 to 6 days at water temperatures of 54 to 59 degrees Fahrenheit (12 to 16 degrees Celsius). Although egg strings are laid in very slow moving water, larvae (tadpoles) can be found in water velocities of up to 1.0 to 1.3 ft per second (30 to 40 cm per second) (Sweet 1992).
Disturbance, Protection, and the Historical Geographical Distributions

As a result of agriculture and urbanization, and the construction, operation, and maintenance of water storage reservoirs, flood control structures, roads, and recreational facilities such as campgrounds and offhighway vehicle parks, many arroyo toad populations have been reduced in size or extirpated (eliminated) due to extensive habitat loss from the 1920s into the 1990s. Although these factors have not dramatically reduced the range of the arroyo toad, within its range many of the habitats that were historically capable of supporting large numbers of arroyo toads have been lost in the last 100 years. Jennings and Hayes (1994) believe that the loss of habitat, coupled with the manipulation of water levels in many central and southern California streams and rivers, predation from introduced aquatic species, and habitat degradation from introduced plant species, caused arroyo toads to be extirpated from 76 percent of their previously occupied habitat in California. Through focused survey efforts over the past few years, a few new arroyo toad populations have been discovered. Because of these recent efforts, however, it is unlikely that many more populations remain undiscovered. The conservation and subsequent protection of the remaining arroyo toad populations are essential for its conservation (Service 1999).

Pursuant to our regulations, we are required to identify the known physical and biological features, i.e., PCEs, essential to the conservation of the arroyo toad, together with a description of any critical habitat that is proposed. In identifying the PCEs, we used the best available scientific and commercial data available. The physical ranges described in the PCEs may not capture all of the variability that is inherent in natural systems that support arroyo toads. The PCEs determined essential to the conservation of arroyo toad include, but are not limited to:

1. Rivers or streams with hydrologic regimes that supply water to provide space, food, and cover needed to sustain eggs, tadpoles, metamorphosing juveniles, and adult breeding toads. Specifically, the conditions necessary to allow for successful reproduction of arroyo toads are:

a. breeding pools with areas less than 12 in (30 cm) deep;

b. areas of flowing water with current velocities less than 1.3 ft per second (40 cm per second); and

c. surface water that lasts for a minimum length of 2 months in most years, i.e., a sufficient wet period in the spring months to allow arroyo toad larvae to hatch, mature, and metamorphose.

2. Lowgradient stream segments (typically less than 6 percent) with sandy or fine gravel substrates that support the formation of shallow pools and sparsely vegetated sand and gravel bars for breeding and rearing of tadpoles and juveniles.

3. A natural flooding regime, or one sufficiently corresponding to a natural regime, that will periodically scour riparian vegetation, rework stream channels and terraces, and redistribute sands and sediments, such that breeding pools and terrace habitats with scattered vegetation are maintained.

4. Riparian and adjacent upland habitats (particularly alluvial streamside terraces and adjacent valley bottomlands that include areas of loose soil where toads can burrow underground) to provide foraging and living areas for subadult and adult arroyo toads.

5. Stream channels and adjacent upland habitats that allow for migration to foraging areas, overwintering sites, dispersal between populations, and recolonization of areas that contain suitable habitat.

Arroyo toads are not distributed uniformly throughout the critical habitat units. Arroyo toad breeding habitat is patchily distributed along the stream courses, and the same is true of appropriate upland habitat. Some areas primarily provide for migration and dispersal between breeding and foraging habitats or allow for dispersal to additional breeding pools that will accommodate increased populations during favorable years. Habitat conditions within streams can change rapidly in response to streamflows and other factors, such as the development and shifting of sand and gravel bars, and creation and disappearance of pools. Terrace and upland habitats, although more stable than streambed and riparian habitats, may change as a result of rainfall, earthquakes, fires, and other natural events. These factors may cause the habitat suitability of given areas to vary over time, thus affecting the distribution of arroyo toads.

The combination of appropriate aquatic, riparian, and upland habitats forms ecologically functional units. These features and the lands that they represent are essential to the conservation of the arroyo toad. All lands identified as essential and proposed as critical habitat contain one or more of the PCEs for the arroyo toad. [[Page 23258]]

Criteria Used To Identify Critical Habitat

The criteria we used to identify critical habitat are identical to the criteria outlined in the final designation previously published in the Federal Register on February 7, 2001 (66 FR 9414).

To evaluate our critical habitat model, we assessed its effectiveness at capturing documented toad locations from studies that focused specifically on surveying toads in upland habitats and studies involving radio telemetry. Holland and Sisk (2000) established extensive pitfall trap arrays at discrete distances from two stream courses and operated these arrays at various periods throughout the year. They had 466 captures of arroyo toads, 35 (7.5 percent) of which were identified as being in upland areas. Those toads were captured at distances that ranged from 49 to 3,855 ft (15 to 1,175 m) from the uplandriparian ecotone (boundary) (Holland and Sisk 2000). For the two areas sampled in that study (Cristianitos Creek and the upper Santa Margarita River), we found that our critical habitat boundaries encompassed an average of 76 percent of the pitfall trapping stations where arroyo toads were detected.

We also assessed studies that involved the tracking of arroyo toads with radio telemetry equipment. For example, in a number of studies by Ramirez (2002a, 2002b, 2002c, 2003), arroyo toads were tracked from the end of breeding activity until the commencement of aestivation, generally May through September. Cumulatively, these four studies involved the tracking of 77 adult arroyo toads in three separate critical habitat units in Orange, San Bernardino, and Los Angeles Counties. All but one of the numerous burrow sites chosen by these arroyo toads fell within our proposed critical habitat boundaries. Proposed Critical Habitat Designation

The approximate area encompassing the proposed critical habitat by county and land ownership is shown in Table 1, and proposed critical habitat units for the arroyo toad in Table 2.
Table 1.Approximate Critical Habitat in Acres (ac) (Hectares (ha)) by County and Land Ownership County Forest Service BLM FWS Military State/Local Tribal Private Total Monterey........................ 0................. 0................. 0................. 6,453 ac (2,612 0................. 0................. 93 ac (38 ha)..... 6,546 ac (2,650 ha). ha). Santa Barbara................... 6,435 ac (2,604 0................. 0................. 0................. 0................. 0................. 4,553 ac (1,842 10,988 ac (4,446 ha). ha). ha). Ventura......................... 6,538 ac (2,645 0................. 0................. 0................. 0................. 0................. 1,105 ac (447 ha). 7,643 ac (3,092 ha). ha). Los Angeles..................... 5,299 ac (2,144 27 ac (11 ha)..... 0................. 0................. 0................. 0................. 7,688 ac (3,111 13,014 ac (5,266 ha). ha). ha). San Bernardino.................. 2,631 ac (1,065 117 ac (47 ha).... 0................. 2,594 ac (1,050 1,166 ac (472 ha). 0................. 9,306 ac (3,766 15,814 ac (6,400 ha). ha). ha). ha). Riverside....................... 1,457 ac (589 ha). 1,047 ac (424 ha). 0................. 0................. 16 ac (6 ha)...... 0................. 966 ac (391 ha)... 3,486 ac (1,410 ha). Orange.......................... 483 ac (195 ha)... 0................. 0................. 107 ac (43 ha).... 2,135 ac (864 ha). 0................. 4,932 ac (1,996 7,657 ac (3,099 ha). ha). San Diego....................... 9,949 ac (4,026 284 ac (115 ha)... 755 ac (305 ha)... 3,338 ac (1,351 3,544 ac (1,434 3,082 ac (1,247 52,613 ac (21, 292 73,565 ac (29,770 ha). ha). ha). ha). ha). ha).

Total....................... 32,792 ac (13,269 1,475 ac (597 ha). 755 ac (305 ha)... 12,492 ac (5,056 6,861 ac (2,775 3,082 ac (1,247 81,256 ac (32,882 138,713 ac (56,133 ha). ha). ha). ha). ha). ha). Table 2.Critical Habitat Units Proposed for the Arroyo Toad Critical habitat unit County Acres Ha Northern
1. San Antonio River............ Monterey........ 6,546 2,649 2. Sisquoc River................ Santa Barbara... 6,574 2,660 3. Upper Santa Ynez River Basin Santa Barbara... 4,414 1,786 (including Indian Barbara and
Mono Creeks).
4. Sespe Creek.................. Ventura......... 4,138 1,675 5. Piru Creek (Upper and Lower). Ventura, L.A.... 3,966 1,605 6. Upper Santa Clara River Basin Los Angeles..... 7,398 2,994 (Castaic, San Francisquito
Creeks).
7. Upper Los Angeles River Basin Los Angeles..... 4,213 1,705 (Big Tujunga, Mill, Alder
Creeks).
Southern
8. Black Star and Baker Creeks.. Orange.......... 172 69 9. San Jacinto River Basin/ Riverside....... 683 277 Bautista Creek.
10. San Juan Creek Basin Orange, 6,285 2,543 (including Trabuco Creek). Riverside.
11. San Mateo Basin Orange, San 4,580 1,853 (Christianitos, Talega, Gabino, Diego.
La Paz Creeks).
12. Lower Santa Margarita Basin San Diego....... 1,840 744 (De Luz, Roblar, Sandia).
13. Upper Santa Margarita Basin Riverside, San 3,628 1,468 (including Temecula and Arroyo Diego.
Seco Creeks).
14. Lower and Middle San Luis San Diego....... 15,376 6,222 Rey Basin (Pala, Keys Creeks).
15. Upper San Luis Rey Basin San Diego....... 11,725 4,745 (above Lake Henshaw).
16. Santa Ysabel Creek (Santa San Diego....... 11,080 4,484 Maria, Guejito, Temescal
Creeks).
17. San Diego River Basin San Diego....... 2,309 934 (including San Vicente Creek).
18. Sweetwater River Basin San Diego....... 9,235 3,737 (Viejas and Peterson Creeks).
19. Cottonwood Creek Basin (many San Diego....... 15,800 6,394 tributaries).
20. Upper Santa Anna River Basin/ San Bernardino.. 1,263 511 Cajon Wash.
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Desert
21. Little Rock Creek (including Los Angeles..... 941 381 Santiago Creek).
22. Upper Mojave (West Fork, San Bernardino.. 14,550 5,848 Deep, Horsethief, Little
Horsethief).
23. Whitewater River............ Riverside....... 1,997 808

Critical habitat includes arroyo toad habitat throughout the species' range in the United States (i.e., Monterey, Santa Barbara, Ventura, Los Angeles, Riverside, San Bernardino, Orange, and San Diego Counties, CA). Lands proposed for critical habitat designation are under private, local agency, county, State, Tribal, and Federal ownership, and have been divided into 23 Critical Habitat Units. Although all of the units we are proposing for critical habitat are within the geographic range of the species, we are not proposing all of the areas known to be occupied by the arroyo toad. We are not proposing any areas outside of the geographical area occupied by the species at the time it was listed. A brief description of each unit, and reasons why it is essential for the conservation of the arroyo toad, are presented below. The units are generally based on geographically distinct river basins. In several instances, a river basin has been broken into two or more units based on human or natural landscape features that effectively separate portions of the basin (e.g., a large reservoir or gorge). Based on observations recorded since 1985, each unit is occupied by arroyo toads.

Jennings and Hayes (1994) estimate that arroyo toads have lost 76 percent of their historic habitat. Although the linear measure of historically occupied streams may not be 4 times what is currently occupied, museum records and data on extant populations indicate that the habitats capable of supporting large numbers of arroyo toads have decreased dramatically in the last 100 years. The reaches that typically support, or historically supported, the highest densities of toads are those in the lower and middle portions of river basins, usually associated with third order (a stream characterization based on size) or larger streams. Many of those reaches have been lost to, or degraded by, urban development, intensive agriculture, water diversions, sand and gravel mining operations, and reservoirs. As discussed in more detail below, with respect to the individual units, we find that all of the areas we are proposing for designation may require special management considerations or protections due to threats to the species and/or its habitat. Such management considerations and protections would benefit the arroyo toad and its habit because: Exotic predators and pets may eat or injure arroyo toads; unnatural water releases from dams can wash away arroyo toad eggs and tadpoles, promote the growth of exotic species, or reduce the availability of open sand bar habitat; water diversions can dry a streambed prior to the completion of metamorphosis from tadpole to toad; toads can be crushed by channel maintenance, road construction, or the plowing of agricultural fields with heavy machinery; toads can be trampled during recreational activities; arroyo toad habitat can be adversely affected by agricultural practices, the invasion of exotic species, inundation from water impoundments, or frequent human use; and water quality can be compromised by runoff from urban, industrial, or agricultural land uses. However, the designation of critical habitat does not carry with it any requirement that landowners or land managers implement any special management or protection programs.

Northern Region

The following seven critical habitat units are located in the Northern Region for the arroyo toad, as discussed in the Recovery Plan (Service 1999). Most of the lands are federally owned, and special management considerations and protections for the toad will likely be addressed through the section 7 consultation process and the development of management plans and conservation strategies. Because the toad populations in this unit have been reduced in size, and their habitat fragmented by road construction, dams, agriculture, and urbanization, it is essential to protect them to reduce further loss of genetic diversity and safeguard against the loss of any one population due to random natural or humancaused events. The Forest Service is the primary landowner of proposed critical habitat within the Northern Region. However, a very small proportion of Forest Service land in this region falls within critical habitat proposed for the arroyo toad. Unit 1: San Antonio River, Monterey County

Unit 1 consists of the San Antonio River and adjacent uplands, from about 2 mi (3 km) upstream of the confluence with Mission Creek downstream to San Antonio Reservoir, a distance of about 17 mi (27 km), and includes small portions of Mission Creek and other tributaries. The unit encompasses approximately 6,546 ac (2,649 ha), of which more than 98 percent is on the Fort Hunter Liggett Military Reservation and the other 2 percent is privately owned.

The northernmost known population of arroyo toads is located here, and is approximately 100 mi (160 km) north of the nearest documented extant population. The onset of breeding activity along the San Antonio River has not been documented prior to the last week in April (Liz Clark, U.S. Army Reserve, pers. comm. 2003), which is several weeks later than the onset of breeding activity documented for arroyo toad populations on the Los Padres National Forest to the south (Sweet 1992). Arroyo toads in this unit may experience climatic conditions not faced by toads at sites found farther south. The protection of this area is essential to maintaining the complete genetic variability of the species and the full range of ecological settings within which it is found, which is essential to the ability of the arroyo toad to adapt to changing environmental conditions. Arroyo toads can be found along the entire length of this segment of the San Antonio River (Service 1999), which is still in a relatively natural state, consists of high quality arroyo toad habitat, and supports probably one of the largest populations within the Northern Region. This area contains all the primary constituent elements, including breeding pools in lowgradient stream segments, sandy substrates, seasonal flood flows, and relatively undisturbed riparian habitat and upland benches for foraging and dispersal.

We consider other areas along the San Antonio River within Fort Hunter Liggett as essential for the conservation of the species, but excluded them from this proposal because they are within
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missionessential training areas (see Exclusions Under Section 4(b)(2)). Thus, we are proposing the majority of the essential lands along the San Antonio River as critical habitat, but we are excluding a portion of the essential lands (less than 50 percent), which are within missionessential training areas on Fort Hunter Liggett (Army 2003). Military operations (including occasional troop movements and weed control) in and near the riparian zone, yet outside of mapped mission essential training areas, may create the need for special management considerations in this unit.

Unit 2: Sisquoc River, Santa Barbara County

Unit 2 consists of 27 mi (43 km) of the Sisquoc River and adjacent uplands, from Sycamore Campground downstream to just below the confluence with La Brea Creek. The unit encompasses approximately 6,574 ac (2,660 ha), of which 61 percent is private land and 39 percent is within the Los Padres National Forest. Upper stretches of the river are within the National Forest and mostly within the San Rafael Wilderness Area. Below the National Forest boundary, the river and adjacent uplands are on rural private lands. This long, undammed stream is occupied arroyo toad habitat and is one of the few remaining major rivers in southern California with a natural flow regime. This area contains all of the primary constituent elements, including breeding pools in lowgradient stream segments, sandy or fine gravel substrates, seasonal flood flows, and relatively undisturbed riparian/upland habitat for foraging and dispersal. This area is essential to maintaining genetic diversity of the species. The protection of this population is essential as it is a core population. Grazing, sand and gravel mining, and limited recreational activities are the primary disturbances to arroyo toad habitat in this unit that may require special management considerations.

Unit 3: Upper Santa Ynez River Basin, Santa Barbara County

Unit 3 is located upstream of Gibraltar Reservoir and incorporates portions of the upper Santa Ynez River, Indian Creek, Mono Creek, and adjacent uplands. The unit encompasses approximately 4,414 ac (1,786 ha) within the boundaries of Los Padres National Forest, with 88 percent on National Forest lands and 12 percent on private non residential inholdings. The segment of the upper Santa Ynez River proposed for designation extends 10 mi (16 km) from Jameson Reservoir downstream to Gibraltar Reservoir. Indian Creek is proposed from the Buckthorn Creek confluence down to its confluence with Mono Creek, a distance of approximately 5 mi (8 km). Mono Creek and associated uplands are proposed for designation for 7.5 mi (12 km) from the first unnamed stream below The Narrows to its confluence with the Santa Ynez River. This area contains all of the primary constituent elements, including breeding pools in lowgradient stream segments, sandy or fine gravel substrates, seasonal flood flows, and relatively undisturbed riparian/upland habitat for foraging and dispersal.

A large and wellstudied arroyo toad population occurs in this area (Sweet 1992, 1993). It is likely a remnant of a much larger population that historically extended downstream below what is now Lake Cachuma and upstream into the area occupied by Jameson Reservoir. The population along Mono Creek is one of the more robust populations of arroyo toads on the Los Padres National Forest and is free of exotic vertebrate predators for much of its length (Jamie Uyehara, Forest Service, pers. comm. 2003). Unit 3 is also the wettest area occupied by arroyo toads in the Northern Region (Teale Data Center 1998; California Irrigation Management Information System 2000).

Arroyo toads in this unit likely experience precipitation and soil moisture conditions not faced by toads at drier sites. Potential adaptations to these conditions make the protection of this area essential to maintaining the genetic diversity of the species. Because it is within, or is surrounded by, National Forest land, this area has favorable habitat conditions for population persistence. The arroyo toad population inhabiting Mono and Indian Creeks is particularly healthy and could be used as a source for the reestablishment of arroyo toads in downstream reaches of the Santa Ynez River, if warranted. The leading threats to arroyo toads in this area, primarily along the lower Santa Ynez River and lower Mono Creek, are from exotic species, recreation, and problems associated with an upstream dam (e.g., sediment trapping, altered hydrological regime, temperature changes). To ensure arroyo toad habitat in this unit is protected, special management considerations or protections may be needed.

Unit 4: Sespe Creek, Ventura County

Unit 4 includes 22 mi (35 km) of Sespe Creek and adjacent uplands, from the lower end of Sespe Gorge (elevation approximately 3,530 ft (1,076 m)) downstream to the confluence with Alder Creek. The unit encompasses approximately 4,138 ac (1,675 ha), of which 87 percent is on the Los Padres National Forest, primarily within the Sespe Wilderness. The remainder is in remote, private inholdings. One of the largest arroyo toad populations on the Los Padres National Forest occurs in this unit along Sespe Creek (Forest Service, in litt. 1999), which is undammed and retains its natural flooding regime. This core population is spread over large areas of excellent habitat, including numerous highquality breeding pools, an abundance of sandy substrates, unimpeded seasonal flood flows, and relatively undisturbed riparian habitat and upland benches for foraging and dispersal (Service 1999). Up to several hundred adult arroyo toads inhabit this reach of the Sespe River (Sweet 1992, 1993), and during years of successful reproduction, such as 2003, thousands of juveniles can be found as well (Tom Murphy, Forest Service, pers. comm. 2003).

Arroyo toads have been found up to 3,300 ft (1,000 m) in elevation in this area, which is one of the highest known occurrences in the Northern Region. The arroyo toads in this unit likely experience temperature extremes or other environmental conditions not faced by toads at lower elevations. Potential adaptations to these conditions make the protection of this area essential for the maintenance of the genetic diversity of the species. In all likelihood, arroyo toad populations in units 4, 5, and 6 historically were part of a large Santa Clara River Basin metapopulation. Ecologically, these units provided a link between the more coastal populations on the Sisquoc and Santa Ynez Rivers, and populations in the Desert Region. Substantial barriers to toad movement now exist between these units, including dams, agriculture, and urban development. Impacts to the Sespe Creek habitat come from recreational activities and exotic predators. Special management considerations or protection may be needed to control and reverse these threats.

Unit 5: Piru Creek, Ventura and Los Angeles Counties

Unit 5 includes Piru Creek and adjacent uplands from the confluence with Lockwood Creek downstream to Pyramid Reservoir (Subunit 5a), and from the confluence with Fish Creek downstream to Lake Piru (Subunit 5b). Subunit 5b also includes Agua Blanca Creek from Devil's Gateway downstream to the confluence with Piru Creek. The unit encompasses approximately 3,966
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ac (1,605 ha), 85 percent of which is within the Los Padres and Angeles National Forests, with the remaining on a few private inholdings. Subunit 5a is in a remote setting within the Los Padres National Forest, and most of subunit 5b is within the Sespe Wilderness.

Although much of the historical arroyo toad habitat along Piru Creek is now inundated by the two reservoirs, a substantial arroyo toad population occurs in this unit (Service 1999). The upper portion of subunit 5a is free of exotic vertebrate predators and the arroyo toad population there has been increasing and expanding over the past several years (J. Uyehara, pers. comm. 2003). The expansion of the population is likely due, in part, to seasonal campground closures and the elimination of suctiondredge mining. Because lower Piru Creek (subunit 5b) is below a large dam, the habitat there has experienced some degradation over the years from perennial water releases, rapid changes in flow volume, excessive flows during the breeding season, and an increased presence of exotic predators. However, future releases from Pyramid Dam are scheduled to more closely mimic natural flows and benefit the arroyo toad (Eva Begley, California State Division of Water Resources, pers. comm. 2003). This should result in an expanded, stable population distributed over areas of goodtoexcellent habitat that is generally undisturbed by human activities. Both upper and lower Piru Creek contain all of the primary constituent elements, including breeding pools in lowgradient stream segments, sandy substrate, seasonal flood flows (modified to some extent below Pyramid Dam), and riparian habitat and upland benches for foraging and dispersal. Special management considerations may be required above and beyond those currently in place to address threats posed by horse and cattle grazing, recreation, and unnatural flows that could potentially be released from Pyramid Dam.

Unit 6: Upper Santa Clara River Basin, Los Angeles County

Unit 6 includes portions the Santa Clara River, Castaic Creek, San Francisquito Creek, and adjacent uplands. The unit encompasses approximately 7,398 ac (2,994 ha) of which 83 percent is private land and 17 percent is within the Angeles National Forest. Subunit 6a, predominantly within the Angeles National Forest, includes Castaic Creek from Bear Canyon downstream to Castaic Lake, and Fish Creek from Cienaga Spring to the confluence with Castaic Creek. Subunit 6b includes Castaic Creek from the downstream edge of The Old Road right ofway (adjacent to Interstate 5) down to the confluence with the Santa Clara River, the Santa Clara River from the confluence with Bouquet Creek down to the confluence with Castaic Creek, and San Francisquito Creek from Drinkwater Canyon downstream to the confluence with the Santa Clara River. Subunit 6c includes the upper Santa Clara River from Arrastre Canyon downstream to the confluence with Bee Canyon Creek.

A healthy population of arroyo toads can be found on Castaic Creek above the reservoir (subunit 6a) (Bill Brown, Forest Service, pers. comm. 2003). Although unknown at the time the Recovery Plan was published (Service 1999), arroyo toads also occupy subunit 6b along the Santa Clara River. This portion of the Santa Clara River was originally excluded from designation as critical habitat for the arroyo toad, in part because we believed that a breeding population of arroyo toads could not be sustained in this area. Recent observations of arroyo toads, including eggs, prove this to be incorrect (Ruben Ramirez, Cadre Environmental, pers. comm. 2003). We had also previously stated (66 FR 9414) that the Natural River Management Plan (NRMP) (Valencia Company 1998) adequately protected this section of the Santa Clara River as a dispersal corridor. However, uplands along this section of the Santa Clara River remain unprotected and threatened by development. Because this section of the Santa Clara River supports a breeding population of arroyo toads, connects arroyo toad habitat in Castaic Creek with San Francisquito Creek, and is in need of further protection, we believe it is essential habitat for the arroyo toad metapopulation in the upper Santa Clara River Basin and, in turn, is essential for the conservation of the species.

Although not detected during a recent survey (Impact Sciences 2001), the Castaic Creek portion of subunit 6b contains highquality arroyo toad habitat within its meandering floodplain and is connected to the occupied reach of the Santa Clara River. The habitat in this river segment is important to the longterm persistence of the Santa Clara River population by allowing for natural population expansion and fluctuation. Although previously included as critical habitat for the arroyo toad, the portion of Castaic Creek from The Old Road Bridge (adjacent to Interstate 5) upstream to Castaic Lagoon contains largely marginal to moderate quality habitat and is not included in this proposal. Arroyo toads have not been detected in this reach during recent surveys (Impact Sciences 2001). Although the habitat looks suitable for arroyo toads, they have not been detected during recent surveys in San Francisquito Creek, which empties into the Santa Clara River (Ed Ervin, U.S. Geological Survey (USGS), pers. comm. 2003). However, in 1997, calling arroyo toad males were heard along San Francisquito Creek near the old St. Francis Dam (Ian Swift, Mountains Recreation and Conservation Authority, pers. comm. 2003). In any event, lower San Francisquito Creek offers an excellent opportunity for further expansion of the arroyo toad population in subunit 6b and is important for the longterm persistence of the Santa Clara River population. The upper portion of the Santa Clara River (subunit 6c) supports a breeding population of arroyo toads (N. Sandburg, in litt. 2001; Rick Farris, Service, pers. comm. 2001; Frank Hovore, Hovore and Associates, in litt. 2001) and has the potential to greatly increase in size with appropriate protection.

Subunits 6a, 6b, and 6c contain all the primary constituent elements, including breeding pools in lowgradient stream segments, sandy substrates, seasonal flood flows, and riparian and upland habitats for foraging and dispersal. The majority of the lands within unit 6 are private, and arroyo toad habitat is adversely affected by urban development, agriculture, recreation, and mining. Exotic species are a concern here as well. Special management considerations or protection may be required in this unit to address these threats. This unit is the easternmost population in the Northern Region, and as such, provides the final link in the range of ecological settings for this region the maintenance of which is essential to the conservation of the species.

Unit 7: Upper Los Angeles River Basin, Los Angeles County

Unit 7 includes portions of Big Tujunga, Mill, and Alder Creeks, and adjacent uplands in the upper Los Angeles River Basin. The unit encompasses approximately 4,213 ac (1,705 ha), of which 64 percent is within the Angeles National Forest and 36 percent is on private lands. This unit is divided into two subunits. Subunit 7a includes 11.8 mi (19 km) of Big Tujunga Creek from below Big Tujunga Dam downstream to Hansen Lake. Subunit 7b encompasses: (1) Approximately 8 mi (13 km) of upper Big Tujunga Creek from immediately above Big Tujunga Reservoir upstream to 1.2 mi (2 km)
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above the confluence with Alder Creek, (2) almost 3.7 mi (6 km) of Mill Creek from the Monte Cristo Creek confluence downstream to Big Tujunga Creek, and (3) 1.9 mi (3 km) of Alder Creek from the Mule Fork confluence downstream to Big Tujunga Creek.

Within the last 15 years, the drainages in this unit have been reported to be occupied by arroyo toads (Forest Service, in litt. 1996; Forest Service 2000; California Natural Diversity Data Base (CNDDB) 2003), and, collectively, these toads represent the only significant known population remaining in the coastal foothills of the San Gabriel Mountains. This unit is essential because it is occupied and contains several primary constituent elements including sandy lowgradient stream segments and highly braided river channels supporting sparse vegetation indicating periodic scouring (USGS 2002). Threats that may require special management considerations include adverse (i.e., timing, amount) water releases from Big Tujunga Dam, exotic predators, such as crayfish and bullfrogs, and exotic plants, such as Arundo donax. This unit also contains populations that occur in highelevation environments that are atypical for arroyo toad and that belong to a metapopulation of the species in the Northern Region.

Southern Region

The following 13 critical habitat units are located in the Southern Region for the arroyo toad and consist of a range of geographic locations from coastal regions to interior mountains. Arroyo toads probably occurred throughout the up and downstream portions of each of these rivers and creek basins, but are now found only in segments of the rivers and creeks, due to loss or change of habitat and exotic predators. Each of these critical habitat units contains river basins that are identified in the Southern Region of the Recovery Plan (Service 1999). Conserving arroyo toad populations in these river basins is necessary for preserving the species' full range of genetic and phenotypic variation and is essential to the conservation of the species and may require special management considerations or protection.
Unit 8: Lower Santa Ana River Basin/Black Star and Baker Creeks, Orange County

Unit 8 includes portions of Black Star and Baker Creeks and adjacent uplands in the lower Santa Ana River Basin. The unit encompasses approximately 172 ac (70 ha) just above Irvine Lake, of which 92 percent is private land and 8 percent is within the Cleveland National Forest. We are proposing a 0.7 mi (1 km) stretch of Black Star Creek and associated uplands and a 1.5mi (0.9km) stretch of lower Baker Canyon and associated uplands upstream from the Cleveland National Forest boundary as critical habitat. We consider other high quality habitats along Santiago Creek as essential but excluded them from this proposed rule because they are within the approved Orange County Central Coastal Subregion Natural Community Conservation Plan (NCCP)/Habitat Conservation Plan (HCP) area (see Discussion in Application of Section 4(a)(3)(B) and Exclusions Under Section 4(b)(2)).

Unit 8 is considered essential because it contains several primary constituent elements including shallow, exposed pools and open habitat with sandy terraces (Harmsworth Associates 2001), lowgradient stream segments with sandy washes, a natural flooding regime that periodically scours riparian vegetation and reworks stream channels and terraces, and riparian and adjacent uplands habitats that provide for foraging habitat and living areas for adult and subadult toads and dispersal between areas containing suitable habitat. Maintaining a population in this unit would enhance the viability of the larger arroyo toad metapopulation that extends across the lower coastal mountain slopes of the Santa Ana Mountains from Santiago Creek to San Mateo Creek (crossing into Units 10 and 11). Toads in this unit are significant to the overall conservation of the species because they are likely a relict population of a larger historical population that existed along the lower Santa Ana River Basin prior to the urbanization of the greater Los Angeles area. This relict population may contain unique genetic variation from a greater Santa Ana River Basin population that, with adequate protection and intermittent gene flow, would promote greater genetic diversity within the metapopulation. Toads were observed in lower Baker Canyon and at the confluence of Silverado Creek and Santiago Creek during the 1970s and 1980s (Robert Fisher, USGS, in litt. 1985; CNDDB 2003). However, surveys performed along Santiago Creek in 1997 failed to detect arroyo toads (Harmsworth Associates 1998), and reportedly no arroyo toads were detected in 2000 during surveys on Irvine Company land within this unit (Harmsworth Associates 2001). These survey efforts, however, did not cover all of the high quality habitats that still exist within this unit (e.g., upper reaches of Baker Canyon). Additional surveys are needed to determine the occupancy status of toads in this unit and their population size. Since suitable habitat still exists, special management considerations, such as augmenting or reestablishing toad populations, may be required for this unit. Threats that may require special management considerations include residential activities near the streams and past commercial sand and gravel removal operations.
Unit 9: San Jacinto River Basin / Bautista Creek, Riverside County

Unit 9 includes portions of Bautista Creek and adjacent uplands in the San Jacinto River Basin. The unit encompasses approximately 683 ac (276 ha), of which 98 percent is within the San Bernardino National Forest and the remaining 2 percent is on State land. We are proposing a 3.1mi (5.1km) discontinuous stretch of Bautista Creek as critical habitat. We also consider highquality habitat along the San Jacinto River as essential from the Sand Canyon confluence downstream to the Soboba Indian Reservation border and along Bautista Creek from the San Bernardino National Forest boundary downstream to near the middle of section 27 (T5S, R1E), where the stream enters a debris basin, but excluded that area from the proposed critical habitat because it is within the Western Riverside MSHCP planning area (see Discussion in Application of Section 4(a)(3)(B) and Exclusions Under Section 4(b)(2)). There is also highquality habitat on the Soboba Indian Reservation along the San Jacinto River and Indian Creek, as well as records of arroyo toads upstream from the Reservation along the San Jacinto River. However, there is uncertainty regarding the amount of highquality habitat and its occupancy by arroyo toads on the Reservation, and therefore, whether this habitat is essential to the conservation of the species. As a consequence, we have not included lands within the Soboda Indian Reservation in the proposed rule. We are interested in working with the Soboba Indian Tribe in determining the occupancy of these areas and in developing a management plan that will address the conservation needs of the arroyo toad.

Unit 9 is comprised of a substantial arroyo toad population in Bautista Creek within the San Bernardino National Forest (USGS 2000, 2001). This population, along with another smaller population on the San Jacinto River (Brock Ortega, Dudek and Associates, in litt. 2001) which is being excluded from proposed critical habitat due to the [[Page 23263]]
Western Riverside MSHCP, likely extends downstream onto Tribal and other private lands, and represents one of the easternmost populations within the species' range. Unit 9 is essential for arroyo toad conservation because it contains several primary constituent elements including low gradient sandy streambeds with slow moving water suitable for arroyo toad breeding and adjacent upland terrace for foraging and burrowing. The arroyo toad population in this unit is one of the easternmost populations and is isolated from other known populations to the south in the Santa Margarita Watershed, to the west in the San Juan Watershed, and from populations to the north in the Santa Ana Watershed. Therefore, conserving this population is important for the species' recovery because it may contain unique genetic, phenotypic and/or behavioral characteristics. The threats that may require special management considerations for this unit include destruction of habitat and mortality of individual toads from recreation and vehicular traffic from nearby roadways (USGS 2001).

Unit 10: San Juan Creek Basin, Orange County

Unit 10 includes portions of San Juan Creek, Bell Canyon, Trabuco Creek, and adjacent uplands in the San Juan Creek Basin. The unit encompasses approximately 6,285 ac (2,544 ha), of which 54 percent is private land, 34 percent is Orange County Park Land (Caspers Wilderness Park and O'Neill Regional Park), and 12 percent is within the Cleveland National Forest. Subunit 10a covers approximately 20.5 mi (33 km) of San Juan Creek from the bottom of Decker Canyon downstream to Interstate 5 and includes about 2.5 mi (4 km) of Bell Canyon from just below Crow Canyon downstream to the confluence with San Juan Creek. Subunit 10b covers approximately 5 mi (8 km) of Trabuco Creek from Falls Canyon to approximately 0.9 mi (1.4 km) downstream of the State Route 241 (Foothill Transportation Corridor) bridge.

Uni

FOR FURTHER INFORMATION CONTACT For information about Monterey, San Luis Obispo, Santa Barbara, and Ventura Counties, northern Los Angeles County, and the desert portion of San Bernardino County, contact Diane Noda, Field Supervisor, Ventura Fish and Wildlife Office, at the address given above (telephone 805/6441766; facsimile 805/6443958). For information about Los Angeles, San Bernardino, Riverside, Orange, and San Diego Counties, contact Jim Bartel, Field Supervisor, Carlsbad Fish and Wildlife Office, at the address given above (telephone 760/ 4319440; facsimile 760/4319624).