BIOLOGICAL RESOURCES TECHNICAL REPORT 

CRITICAL HABITATS AND THREATENED AND 

ENDANGERED SPECIES 

Brightline West Cajon Pass High-Speed Rail Project 

October, 2022 

Prepared for 

Federal Railroad Administration 

Prepared by 

HNTB 

BRIGHTLINE WEST CAJON PASS HIGH-SPEED RAIL PROJECT 

Contents 

Abbreviations and Acronyms ....................................................................................................... iv 

1. Executive Summary................................................................................................................. 1 

1.1. Affected Environment.................................................................................................... 1 

1.2. Environmental Consequences and Mitigation ............................................................. 14 

2. Introduction .......................................................................................................................... 39 

3. Project Description................................................................................................................ 41 

3.1. Background.................................................................................................................. 41 

3.2. Project Area ................................................................................................................. 41 

3.3. Purpose of and Need for the Project ........................................................................... 41 

3.4. Alternatives ................................................................................................................. 48 

3.5. Build Alternative .......................................................................................................... 48 

3.6. No Build Alternative..................................................................................................... 52 

4. Federal Regulations............................................................................................................... 53 

5. Methodology......................................................................................................................... 57 

5.1. Study Area ................................................................................................................... 57 

5.2. Existing Information..................................................................................................... 58 

5.3. Wildlife Habitats and Species Information................................................................... 58 

5.4. Habitat Impact Area Analysis....................................................................................... 60 

6. Affected Environment ........................................................................................................... 61 

6.1. Section 1 – High Desert................................................................................................ 61 

6.2. Section 2 – Cajon Pass ................................................................................................. 62 

6.3. Section 3 – Greater Los Angeles .................................................................................. 63 

6.4. Existing Habitat Conservation Plan Areas and Conservation Lands ............................. 64 

6.5. Wildlife Habitats .......................................................................................................... 64 

6.6. Habitat Connectivity and Wildlife Movement.............................................................. 71 

6.7. Migratory Birds ............................................................................................................ 72 

6.8. Bald and Golden Eagles................................................................................................ 73 

6.9. ESA-Listed and Candidate Species in the Study Area ................................................... 74 

6.10. Designated Critical Habitats......................................................................................... 80 

6.11. Background Noise........................................................................................................ 82 

6.12. Santa Ana Winds.......................................................................................................... 82 

6.13. Biological Resources Relevant to Tribes....................................................................... 82 

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7. Environmental Consequences and Mitigation....................................................................... 89 

7.1. Construction Effects..................................................................................................... 89 

7.2. Operational Effects ...................................................................................................... 99 

7.3. Cumulative Effects ..................................................................................................... 105 

7.4. Impact Avoidance and Minimization Measures......................................................... 105 

7.5. Proposed Compensation for Unavoidable Impacts.................................................... 116 

8. Consultation with USFWS.................................................................................................... 119 

9. References .......................................................................................................................... 121 

Figures 

Figure 1. Conservation Lands and Designated Critical Habitat in the Project Vicinity .................10 

Figure 2. Wildlife Corridors in the Project Area, as Mapped by San Bernardino County.............13 

Figure 3. Project Area and Vicinity ..............................................................................................43 

Tables 

Table 1. Area of Wildlife Habitat within the Limits of Disturbance, Including Temporary 

and Permanent Disturbance and all Project Elements .................................................4 

Table 2. ESA-Listed Plant Species Potentially Present in the Study Area and Effects 

Determinations.............................................................................................................5 

Table 3. ESA-Listed Wildlife Species with Potential to Occur in the Study Area and Effects 

Determination ..............................................................................................................6 

Table 4. USFWS-Designated Critical Habitat in the Study Area and Effects Determination ..........7 

Table 5. Summary of Conservation Areas Within 1 Mile of the Study Area ..................................8 

Table 6. Wildlife Habitat Types Present in Conservation Areas Within 1 Mile of the Study 

Area ............................................................................................................................11 

Table 7. Temporary Impacts on Wildlife Habitat Types in All Project Sections ...........................16 

Table 8. ESA-Listed Plant Species Likely to be Affected by Project Construction ........................17 

Table 9. ESA-Listed Wildlife Species Likely to be Affected by Project Construction ....................18 

Table 10. Permanent Impacts on Wildlife Habitat, by Habitat Types ..........................................21 

Table 11. ESA-Listed Plant Species Likely to be Affected by Project Operation...........................22 

Table 12. ESA-Listed Wildlife Species which May be Affected by Project Operation ..................23 

Table 13. Avian Avoidance Exclusion Areas and Closure Dates...................................................28 

Table 14. Mapped Habitat Types within the Study Area, by California Wildlife Habitat 

Type............................................................................................................................65 

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Table 15. ESA-Listed Species that May Occur in the Project Area ...............................................74 

Table 16. ESA-Listed Species, Suitable Habitat, and Designated Critical Habitat that May 

Occur in the Project Area............................................................................................80 

Table 17. Plants Possibly Present in the Study Area that May Contribute to Essential 

Practices and Traditional Cultural Practices................................................................83 

Table 18. Wildlife Species Present in Project Vicinity that May Contribute to Essential 

Practices of Indigenous Communities.........................................................................85 

Table 19. Section 1, High Desert, Temporary Impacts on Wildlife Habitat Types........................92 

Table 20. Section 2, Cajon Pass, Temporary Impacts on Wildlife Habitat Types .........................93 

Table 21. Section 3, Greater Los Angeles, Temporary Impacts on Wildlife Habitat Types ..........94 

Table 22. ESA-Listed Species Potentially Affected in Section 1, High Desert...............................94 

Table 23. ESA-Listed Species Potentially Affected in Section 2, Cajon Pass.................................95 

Table 24. ESA-Listed Species Potentially Affected in Section 3, Greater Los Angeles..................96 

Table 25. Section 1, High Desert, Areas of Permanent Impacts on Wildlife Habitat Types .......102 

Table 26. Section 2, Cajon Pass, Areas of Permanent Impacts on Wildlife Habitat Types .........102 

Table 27. Section 3, Greater Los Angeles, Areas of Permanent Impacts on Wildlife 

Habitat Types............................................................................................................103 

Table 28. Avian Avoidance Exclusion Areas and Closure Dates ................................................107 

Appendices 

Appendix A Temporary and Permanent Wildlife Habitat Impacts Maps 

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Abbreviations and Acronyms 

ADT average daily traffic 

ARRIVE Advanced Regional Rail Integrated Vision – East 

BLM US Bureau of Land Management 

BMP best management practice 

BGEPA Bald and Golden Eagle Protection Act 

CAL FIRE California Department of Forestry and Fire Protection 

CalSTA California State Transportation Agency 

Caltrans California Department of Transportation 

CALVEG Classification and Assessment with LANDSAT of Visible Ecological Groupings 

CGP Construction General Permit 

CHP California Highway Patrol 

CNDDB California Natural Diversity Database 

CWHR California Wildlife Habitat Relationship System 

dBLmax Maximum sound level during a sound monitoring event 

dBA A-weighted decibel(s) 

EIR Final Environmental Impact Report 

ESA federal Endangered Species Act 

FRA Federal Railroad Administration 

GHG greenhouse gas 

GIS geographic information systems 

HCP Habitat Conservation Plan 

HOV high-occupancy vehicle 

HSR high-speed rail 

I- Interstate 

IPaC Information for Planning and Consultation 

Leq Equivalent continuous sound level 

LOD limit of disturbance 

LOS level of service 

MBTA Migratory Bird Treaty Act 

MOU memorandum of understanding 

mph miles per hour 

NAAQS National Ambient Air Quality Standards 

NRCS Natural Resources Conservation Service 

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Project Cajon Pass High-Speed Rail Project 

SBCFCD San Bernardino County Flood Control District 

SBCTA San Bernardino County Transportation Authority 

SCAG Southern California Association of Governments 

SCE Southern California Edison 

SR State Route 

SWMP Stormwater Management Plan 

SWPPP Stormwater Pollution Prevention Plan 

TCP Traditional Cultural Properties 

substation traction power substation 

TWPC Temporary Water Pollution Control 

U.S.C. United States Code 

USDA US Department of Agriculture 

USDOT US Department of Transportation 

USFS US Department of Agriculture, Forest Service 

USFWS US Fish and Wildlife Service 

VHT vehicle hours traveled 

VMT vehicle miles traveled 

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1. Executive Summary 

DesertXpress Enterprises, LLC (doing business as “Brightline West”) proposes to construct and 

operate a passenger high-speed rail system capable of speeds up to 180 miles per hour (mph) 

covering 47.9 miles between Victor Valley and Rancho Cucamonga, California. The Brightline 

West Cajon Pass High-speed Rail (“Proposed Action” or “Project”) would be constructed and 

operated under a lease agreement with the California Department of Transportation (Caltrans) 

for the use of the Interstate 15 (I-15) right-of-way. Additional agreements between Brightline 

West and Caltrans will include right-of-way use; design and construction oversight; 

reimbursement; landscape and restoration following construction; and operations and 

maintenance. 

The Proposed Action includes construction of two passenger stations, a traction power 

substation, and alterations of existing transportation infrastructure, including expansion of 

existing I-15 lane areas at the outer edges of the existing roadway to enable rail to travel in the 

I-15 median. 

1.1. Affected Environment 

1.1.1. Regulatory Setting 

The following existing federal regulations and regional plans are relevant to federally protected 

species and their associated habitats: 

• Federal Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531–1543), as amended: The US 

Fish and Wildlife Service (USFWS) has jurisdiction over ESA-listed plants, animals, and fish 

and their critical habitats. For the Project, the Federal Railroad Administration (FRA) is the 

lead federal agency responsible for consultation with USFWS to ensure that the Project will 

not jeopardize the continued existence of an endangered or threatened species or destroy 

or adversely modify critical habitat. Critical habitat is defined in the ESA, Section 3(5)(A), as: 

Specific areas within the geographic area occupied by the species on which 

are found those physical or biological features essential to the conservation 

of the species and which may require specific management considerations or 

protection. 

Critical habitat is further defined by the ESA as: 

Specific areas outside the geographical area occupied by the species at the 

time it is listed but a determination has been made that such areas are 

essential for the conservation of the species. 

Implementation of ESA Section 7 (a)(2), which requires FRA to consult with 

USFWS, includes analyses of impacts on designated critical habitat, analyses of 

impacts on listed species, and analyses of indirect and cumulative impacts on 

listed species. 

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• Migratory Bird Treaty Act of 1918 (MBTA; 16 U.S.C. Part 703), as amended: The MBTA 

authorizes the United States Secretary of the Interior to protect and regulate the taking 

of migratory birds. The MBTA protects migratory birds, their occupied nests, and their 

eggs and prevents the taking of birds listed as “migratory.” The MBTA defines migratory 

birds broadly and includes common songbirds, waterfowl, shorebirds, hawks, owls, 

eagles, ravens, crows, native doves and pigeons, swifts, martins, and swallows. 

• Bald and Golden Eagle Protection Act (BGEPA; 16 U.S.C. § 668-668c): The Bald and Golden 

Eagle Protection Act (BGEPA) prohibits the taking or possession of and commerce in bald 

and golden eagles, with limited exceptions. Under the BGEPA, it is a violation to “...take, 

possess, sell, purchase, barter, offer to sell, transport, export or import, at any time or in 

any manner, any bald eagle commonly known as the American eagle, or golden eagle, alive 

or dead, or any part, nest, or egg, thereof....”Under the BGEPA “take” is defined as to 

include pursue, shoot, shoot at, poison, wound, kill, capture, trap, collect, molest, and 

disturb. 

“Disturb” is further defined as follows:

to agitate or bother a bald or golden eagle to a degree that causes, or is likely 

to cause, based on the best scientific information available (1) injury to an 

eagle, (2) a decrease in its productivity, by substantially interfering with 

normal breeding, feeding, or sheltering behavior, or (3) nest abandonment, 

by substantially interfering with normal breeding, feeding, or sheltering 

behavior (50 CFR 22.3). 

• Executive Orders 13112 and 13751, National Invasive Species: Executive Orders 13112 

and 13751, Invasive Species, direct all federal agencies to prevent and control 

introductions of invasive nonnative species, and to not authorize or carry out actions 

that are likely to cause or promote invasive species. Federal agencies should minimize 

the economic, ecological, and human health impacts caused by invasive species 

infestations. The Executive Orders require that the National Environmental Policy Act 

process include determinations of the likelihood of introducing or spreading invasive 

species as well as a description of measures being taken to minimize their potential 

harm. 

1.1.2. Methodology 

This Biological Resources Technical Report prepared for the Project was based on literature and 

database reviews, compilation of available information including maps, and an analysis of 

potential direct and indirect effects on ESA-listed species and designated critical habitats. 

The following available environmental documentation was utilized to assess the likelihood of 

plants, animals, and suitable habitat presence in the study area: 

• Official List of Species and Critical Habitats (USFWS 2022d) 

• Information for Planning and Consultation (IPaC; USFWS 2022a) – Data regarding ESA-listed 

species and locations of designated critical habitat 

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• The California Natural Diversity Database (CNDDB 2022) –Mapped information on plant and 

animal species locations 

• California Wildlife Habitat Relationship (CWHR) System –System that provides information 

on wildlife habitat types 

Spatial distribution of wildlife habitat types was obtained from two available mapped sources: 

• Wildlife habitats mapped by the Desert Renewable Energy Conservation plan (Menke et al. 

2013) covering Section 1 and Section 2 

• Wildlife habitats mapped by South Coast polygon from CALVEG (USFS 2020) covering 

Section 2 and Section 3 

State-protected sensitive, threatened, or endangered species or state protected sensitive 

habitats were not evaluated for this federal interstate transportation project. No local agency 

information regarding sensitive plants or animal species were reviewed for this report. No field 

surveys or other field studies were performed for this analysis. Supplemental field studies are 

planned to occur as part of preconstruction activities. 

1.1.3. Study Area 

The study area for the quantitative impact analysis was defined as the limit of direct ground 

disturbance, including permanent impacts, and temporary disturbance that may occur during 

construction. Indirect potential effects were evaluated qualitatively. Limits of direct ground 

disturbance were mapped using the preliminary engineering design plans of June 2022 (design 

plans). Maps in Appendix A show the limits of ground disturbance. 

Approximately 2,900 acres are within the limits of ground disturbance for the Project 

alignment. The study area included the existing I-15 in the Project area, along with areas 

adjacent to the existing highway within Caltrans right-of-way. 

1.1.3.1. Habitat Conservation Plan Areas and Conservation Land 

Habitat Conservation Plans (HCPs) have been produced for areas covering the study area or 

adjacent to the study area. 

The northern extent of the rail alignment in Section 1, High Desert, lies within the West Mojave 

Plan planning area. The West Mojave Plan focuses on conservation of desert tortoise and 

Mohave (sic) ground squirrel, along with sensitive plants and animals that occur in the 

associated natural communities. 

The Western Riverside County Multiple Species Habitat Conservation Plan (Riverside County 

2004) covers 1.26 million acres in western Riverside County, with the nearest extent lying 

approximately 5 miles south of the Project. 

1.1.4. Wildlife Habitats 

From north to south, the study area begins in the arid Mojave Desert (High Desert), crosses a 

mountain range (San Gabriel Mountains), and travels into the marine-influenced, 

Mediterranean climate of the Los Angeles basin. The route has high biotic, climatic, and 

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geographic diversity. The study area comprises various wildlife habitat types that allow for 

habitat connectivity and wildlife movement. Table 1 lists wildlife habitat types mapped in the 

study area. 

Given the prevalence of transportation infrastructure, Urban habitat (including areas of 

developed and impervious surfaces) was the most common habitat type in the study area. 

Table 1. Area of Wildlife Habitat within the Limits of Disturbance, Including Temporary and 

Permanent Disturbance and all Project Elements 

Wildlife Habitat Type Habitat Codea 

Total Area 

(acres) 

Alkali Desert Scrub ASC 4.46 

Annual Grassland AGS 18.88 

Barren BAR 4.57 

Chamise-Redshank Chaparral, Mixed Chaparral CRC, MCH 3.19 

Coastal Scrub CSC 15.31 

Desert Riparian DRI 9.99 

Desert Scrub DSC 204.17 

Desert Scrub, Desert Wash DSW, DSW 1.38 

Desert Wash DSW 44.16 

Joshua Tree JST 0.35 

Juniper JUN 2.82 

Mixed Chaparral MCH 134.59 

Riverine RIV 14.98 

Sagebrush SGB 22.02 

Urban URB 2,415.81 

Valley Foothill Riparian VRI 1.94 

Total 2,899.81 

a. California Wildlife Habitat Relationship (CWHR) codes are used on maps in Appendix A. 

1.1.5. ESA-Listed Species 

Two plant species, six wildlife species, one ESA candidate species, and three USFWS-designated 

critical habitat areas were identified to occur in the Project area. Formal consultation between 

FRA and the USFWS is underway regarding ESA-listed species and designated critical habitats. A 

Biological Assessment is in preparation to analyze the effect on ESA-listed species and 

designated critical habitats. Preliminary effects determinations have been made based on 

analysis presented in the Biological Assessment and these are provided in the tables presented 

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in the sections below. The determinations have not been reviewed or approved by USFWS at 

the time of writing. 

1.1.5.1. Plants 

Native plant communities occur along the Project alignment throughout the study area. The 

Biological Resources Technical Report describes specific locations of plant communities mapped 

as wildlife habitats located within the study area. 

Table 2 lists the ESA-listed plant species that were identified using information from the Official 

List from USFWS (2022). Santa Ana River woolly-star and slender-horned spineflower occur 

within the study area. Suitable habitat for the woolly-star is present within Cajon Canyon and 

Lytle Creek (Buck-Diaz and Evans 2011) in the study area. Populations of slender-horned 

spineflower are known from the Lytle Creek, Cajon Canyon, and Cajon Wash areas in the 

project area (USFWS 2010). 

Table 2. ESA-Listed Plant Species Potentially Present in the Study Area and Effects 

Determinations 

Species Name Federal Status 

Suitable Habitat 

Likely Present Effects Determination 

Plants 

Braunton's milk-vetch 

(Astragalus brauntonii) 

Endangered No No Effect 

San Diego ambrosia 

(Ambrosia pumila) 

Endangered No No Effect 

Santa Ana River woolly-star 

(Eriastrum densifolium ssp. sanctorum) 

Endangered Yes May Affect, Likely to Adversely 

Affect 

Slender-horned spineflower 

(Dodecahema leptoceras) 

Endangered Yes May Affect, Likely to Adversely 

Affect 

Source: USFWS 2022d 

1.1.5.2. Wildlife 

Table 3 lists the ESA-listed wildlife potentially present in the study area (USFWS 2022d). Arroyo 

(southwestern) toad, coastal California gnatcatcher, least Bell’s vireo, southwestern willow 

flycatcher, western yellow-billed cuckoo, San Bernardino Merriam’s kangaroo rat, and desert 

tortoise likely occur within the study area. Table 3 provides an effects determination for each 

species. 

In the project vicinity, one population of arroyo toad had been identified along Cajon Canyon 

on the west side of I-15 on the San Bernardino National Forest (CNDDB 2022). Arroyo toad has 

likely been extirpated from the Mojave River crossing vicinity. 

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Table 3. ESA-Listed Wildlife Species with Potential to Occur in the Study Area and Effects 

Determination 

Species Name Federal Status 

Suitable Habitat 

Likely Present Effects Determination 

Amphibians 

Arroyo (southwestern) toad 

(Anaxyrus californicus) 

Endangered Yes May Affect, Likely to Adversely 

Affect 

Mountain yellow-legged frog 

(Rana muscosa) 

Endangered No No Effect 

Birds 

California condor 

(Gymnogyps californianus) 

Endangered No No Effect 

Coastal California gnatcatcher 

(Polioptila californica californica) 

Threatened Yes May Affect, Not Likely to 

Adversely Affect 

Least Bell's vireo 

(Vireo bellii pusillus) 

Endangered Yes May Affect, Not Likely to 

Adversely Affect 

Southwestern willow flycatcher 

(Empidonax traillii extimus) 

Endangered Yes May Affect, Not Likely to 

Adversely Affect 

Western yellow-billed cuckoo 

(Coccyzus americanus) 

Threatened Yes May Affect, Not Likely to 

Adversely Affect 

Fish 

Mohave tui chub 

(Gila bicolor ssp. mohavensis) 

Endangered No No Effect 

Santa Ana sucker 

(Catostamus santaanae) 

Endangered No No Effect 

Insects 

Delhi Sands flower-loving fly 

(Rhaphiomidas terminatus abdominalis) 

Endangered No No Effect 

Mammals 

San Bernardino Merriam’s kangaroo rat

(Dipodomys merriami parvus) 

Endangered Yes May Affect, Likely to Adversely 

Affect 

Reptiles 

Desert tortoise 

(Gopherus agassizii) 

Threatened Yes May Affect, Not Likely to 

Adversely Affect 

Source: USFWS 2022d 

Suitable habitat for the coastal California gnatcatcher is present within the Riversidean alluvial 

fan sage scrub and other plant communities that occur at Cajon Wash and Lytle Creek (Buck6 BIOLOGICAL RESOURCES TECHNICAL REPORT, OCTOBER 2022 
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Diaz and Evans 2011). The bird has been documented adjacent to I-15 around Lytle Creek and in 

northeastern Rancho Cucamonga (CNDDB 2022). 

Past observations of paired least Bell’s vireos and nests suggest nesting activity has occurred in 

the project vicinity along the Mojave River, from the Mojave Narrows Regional Park to Bell 

Mountain Wash near Victorville (USFWS 1994a); this reach includes the Mojave River crossing 

by the Proposed Action. Recent sightings of the birds have occurred along the Mojave River, 

just north of the I-15 crossing (CNDDB 2022). 

Suitable habitat for the southwestern willow flycatcher may be present, and the species has 

been spotted multiple times throughout Cajon Canyon (CNDDB 2022). Riparian habitat in the 

Mojave River also provides suitable habitat and is designated as critical habitat for this species. 

The potential range for yellow-billed cuckoo includes the entire study area, although species 

presence is anticipated only at the Mojave River crossing, with recent sightings reported in this 

vicinity (USFWS 2022b). Riparian vegetation present along the Mojave River corridor includes 

patches of cottonwood-willow riparian forest potentially suitable for this species for stopovers 

during migration and possibly nesting. 

Suitable habitat for San Bernardino Merriam’s kangaroo rat in Cajon Canyon and Lytle Creek 

may exist within the study area. The CNDDB reports multiple sightings of the kangaroo rat 

around Etiwanda Creek Wash and San Sevaine Canyon Wash west of the project area, and at 

Cajon Canyon in the vicinity of the study area. Suitable habitat is also present at the 

I-15/I-10 interchange where the alignment crosses Cajon Wash (CNDDB 2022). Suitable habitat 

for the desert tortoise may exist in the study area along Section 1, High Desert, and Section 2, 

Cajon Pass. 

The monarch butterfly, a candidate species, is widespread and is known to occur in many 

locations in San Bernardino County. Migrating monarchs would pass through the study area to 

and from inland areas and to and from overwintering sites along the California coast. 

1.1.6. Designated Critical Habitat 

Arroyo toad, southwestern willow flycatcher, and San Bernardino Merriam’s kangaroo rat 

critical habitat occur within the study area (USFWS 2022d; Table 4). Maps in Appendix A 

illustrate the locations of the designated critical habitats. 

Table 4. USFWS-Designated Critical Habitat in the Study Area and Effects Determination 

Species Name Federal Status 

Location in Study 

Area Effects Determination 

Critical Habitat 

Arroyo (southwestern) toad 

critical habitat 

Designated Cajon Canyon May Affect, Likely to Adversely 

Affect 

Southwestern willow flycatcher 

critical habitat 

Designated Mojave River May Affect, Likely to Adversely 

Affect 

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San Bernardino Merriam’s kangaroo rat

critical habitat 

Designated Lytle Creek and 

Cajon Wash 

May Affect, Likely to Adversely 

Affect 

Source: USFWS 2022a and 2022d 

Arroyo toad critical habitat is mapped along Cajon Canyon adjacent to the I-15 corridor, from 

northwest of I-215/I-15 interchange to the I-15/SR 138 junction. 

The study area intersects with San Bernardino Merriam’s kangaroo rat designated critical 

habitat within Lytle Creek and Cajon Wash, from northeast of the I-15/SR 210 interchange to 

northwest of the I-15/I-215 interchange. 

Southwestern willow flycatcher critical habitat is mapped at the Mojave River where the I-15 

corridor crosses the Mojave River. 

1.1.7. Bald and Golden Eagles and Migratory Birds 

Migratory birds pass through the Project region in fall and spring along the Pacific Flyway. The 

Pacific Flyway migratory corridor extends from Alaska to the southern tip of South America and 

includes the entire width of California. Habitats with cover and water sources are critical stopover points for migrating birds. In the Project vicinity, the riparian habitats of the Mojave River, 

Cajon Canyon, Cajon Wash, and Lytle Creek provide a vital link for migratory birds. 

Bald eagle (Haliaeetus leucocephalus) and golden eagle (Aquila chrysaetos) are large raptors 

present in the region and may use the Project vicinity. Breeding adult pairs, non-breeding 

juveniles, and subadult eagles may occur as residents and as transient migrants. 

Migratory birds of conservation concern warrant special attention (USFWS 2022a) and are of 

concern throughout their range. Birds of conservation concern potentially in the study area 

include the following: Allen’s hummingbird (Selasphorus sasin), black-chinned sparrow (Spisella 

atrogularis), California thrasher (Toxostoma redivivum), Cassin’s finch (Carpodacus cassinii), 

Clark’s grebe (Aechmophorus clarkii), common yellowthroat (Geothlypis trichas sinuosa), 

Costa’s hummingbird (Calypte costae), Lawrence’s goldfinch (Carduelis lawrencei), long-eared 

owl (Asio otus), Nuttall’s woodpecker (Picoides nuttallii), oak titmouse (Baeolophus inornatus), 

olive-sided flycatcher, (Contopus cooperis), rufous-winged sparrow (Aimophilia carpalis), 

tricolored blackbird (Aeglaius tricolor), , and wrentit (Chamaea fasicata). 

1.1.8. Conservation Areas Within the Study Area Vicinity 

Seven conservation areas occur within 1 mile of the study area (Table 5). Locations of 

conservation areas are shown in Figure 1. In total, conservation areas cover approximately 

1,000 acres in the vicinity of the Project. None of these areas overlap with Caltrans right-ofway. Some of the conservation areas are also within designated critical habitat. 

Table 5. Summary of Conservation Areas Within 1 Mile of the Study Area 

In Vicinity of Study Area 

Project Section Parcel Name Administrator 

Area 

(acres) 

1 – High Desert Wildlands Conservancy The Wildlands Conservancy 96 

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In Vicinity of Study Area 

Project Section Parcel Name Administrator 

Area 

(acres) 

2 – Cajon Pass Kane Ranch Rivers and Lands Conservancy 27 

2 – Cajon Pass Cajon Canyon 1 San Manuel Band of Indians 26 

2 – Cajon Pass Cajon Canyon 2 The Wildlands Conservancy 4 

3 – Greater Los Angeles Lytle Creek CDFW Owned and Operated Lands 63 

3 – Greater Los Angeles Glen Helen Regional Park San Bernardino County 399 

3 – Greater Los Angeles Lytle Creek Ranch Development 

Proposed Conservation Area 

Lytle Creek Ranch Development 394 

Total area within 1 mile of study area proposed for or under conservation 1,009 

Table 6 summarizes wildlife habitat types present at each conservation area within 1 mile of 

the study area. Most conservation-area parcels listed in the table include a least a small 

portion, if not more, of Urban wildlife habitat. 

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Figure 1. Conservation Lands and Designated Critical Habitat in the Project Vicinity 

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Table 6. Wildlife Habitat Types Present in Conservation Areas Within 1 Mile of the Study Area 

Habitat Type 

Area Within Conservation Areas (acres) 

Lytle Creek 

Ranch 

Kane 

Ranch 

Glen Helen 

County Park 

Lytle Creek 

Ranch 

(proposed) 

San Manuel 

Band of 

Indians 

The Wildlands 

Conservancy Total 

Annual Grassland 7.5 0.2 7.7 

Barren 0.0 4.3 33.9 38.2 

Desert Riparian 7.7 1.8 9.5 

Desert Scrub 6.5 4.4 19.4 30.3 

Desert Wash 57.8 13.8 165.4 236.9 

Joshua Tree 9.5 9.5 

Juniper 14.7 14.7 

Lacustrine 6.3 6.3 

Mixed Chaparral 1.1 201.9 4.4 8.8 33.8 249.9 

Riverine 1.2 0.5 161.0 162.7 

Urban 4.1 11.7 164.8 16.2 10.1 23.0 229.9 

Valley Foothill 

Riparian 

6.8 6.8 

Total 63.0 27.0 399.1 387.9 25.0 100.3 1,002.5 

1.1.9. Habitat Connectivity and Wildlife Movement 

Corridors where wildlife move between larger habitat patches are generally referred to as 

habitat linkages or wildlife movement corridors. They allow for short-term movements, 

long-term dispersal, or one-time emigration. Wildlife movement corridors allow species to 

travel through a landscape or they may serve as core habitat for some species. The existing I-15 

highway corridor is a barrier to wildlife movement, except in locations where existing culverts 

or bridge structures enable wildlife movement. A wildlife movement corridor occurs along 

Cajon Canyon, linking the San Bernardino Valley and the Mojave Desert (generally north-south 

direction). I-15 is within and parallels this corridor. Wildlife crossing east-to-west in the 

mountains through Cajon Canyon must cross I-15 and four active freight rail lines. The Mojave 

River is a known wildlife corridor and I-15 crosses above the river corridor. 

San Bernardino County mapped major wildlife corridors and wildlife focused policy areas, 

including the location of the north-south wildlife corridors through Cajon Canyon (Figure 2). 

Policy areas on the figure indicate locations where San Bernardino County wildlife management 

policies have been applied due to the presence of federally designated critical habitat and 

assumed presences of sensitive species. 

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Barriers to wildlife movement occur where development has fragmented habitat or otherwise 

results in effects that cause wildlife to avoid an area. A 2012 study evaluated linkages between 

wildlife habitat locations in the Mojave Desert portion of the study area (Penrod et al. 2012) 

CDFW in conjunction with federal partners has identified barriers to priority movement along 

highway corridors. One priority barrier to wildlife crossing has been identified in the study area 

- Barrier ID W060 I-15 at Cajon Pass, where approximately 2.7 miles of highway between Cajon 

Junction and Baldy Mesa Road on I-15 lack suitable wildlife crossings for mule deer, mountain 

lion, bear, and bighorn sheep (CDFW 2020). 

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Figure 2. Wildlife Corridors in the Project Area, as Mapped by San Bernardino County 

1.1.10. Background Noise 

Background noise in the study area is principally generated by existing traffic along I-15. 

Additional noise is generated at locations of the alignment that are aligned with the two Class 1 

rail alignments, including three BNSF tracks and one Union Pacific Railroad track. 

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A generalized estimate for existing traffic noise was determined to be approximately 

72 A-weighted decibels (dBA) of equivalent continuous sound (Leq) in air 50 feet from the outer 

edge of the highway (SCAG, SANBAG, and Caltrans 2005). Existing ambient noise levels in the 

Project area were measured in October and November 2021 by the Project in urban noise 

sensitive areas where human receptors would be present (Cross-spectrum Acoustics 2022). 

Equivalent continuous sound (Leq) ranged from 54.5 to 76.7 BA, including for both short-term 

(1-hour) and long-term (24-hour) monitoring adjacent to I15. Noise levels adjacent to the 

highway in Cajon Pass would include noise from truck climbing and descending lanes on the 

6 percent grade and noise levels could be slightly higher in this location than those recorded in 

the urban areas. 

1.1.11. Santa Ana Winds 

Down-slope, dry, high-wind events, known as Santa Ana winds, with sustained winds in excess 

of 40 miles per hour funnel through Cajon Pass seasonally, and sometimes at extreme forces, 

such as 74 miles per hour or greater. In addition to Cajon Canyon, North Fontana in the vicinity 

of I-15 and the Lytle Creek area are known to be affected by these extreme force wind events. 

The Old Fire, which burned a wide area across Cajon Pass, including the project area, was 

associated with a Santa Ana wind event. 

1.1.12. Hydrologic Features 

Hydrologic features crossed by the Project include river, stream, and wash systems. These 

include Bell Mountain Wash, Oro Grande Wash, the Mojave River, Cajon Creek, Crowder 

Canyon Wash, Cleghorn Wash, Lytle Creek, Cajon Wash, Hawker-Crawford Channel, San Sevaine 

Channel, East Etiwanda Creek Channel and Day Creek Channel and several small unnamed 

drainage features. The San Bernardino County Flood Control District (SBCFCD) maintains the 

Mojave River reach, the Oro Grande Wash, Hawker-Crawford Channel, San Sevaine Channel, 

East Etiwanda Creek Channel. and Day Creek Channel in the project vicinity. The California 

Aqueduct is crossed by the Project and was mapped as Lacustrine habitat type. 

1.2. Environmental Consequences and Mitigation 

1.2.1. No Build Alternative 

The No Build Alternative would involve no action to create a passenger high-speed rail (HSR) 

system in the median and immediately alongside the I-15 highway between Victor Valley and 

Rancho Cucamonga. The existing I-15 corridor would remain operational without improving the 

major points of congestion or transportation capacity deficiencies along the highway. The No 

Build Alternative would not result in temporary or permanent impacts on ESA-listed species and 

their habitats or on designated critical habitat because no activities or construction would 

occur. 

1.2.2. Construction of Build Alternative 

Construction of the railway may modify wildlife habitat directly and indirectly by affecting 

habitats, vegetation and soils from construction-generated dust, noise, hydrologic 

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modifications, facilitation of invasive species, and changes in habitat elements that increase or 

decrease populations of predators or prey species. These effects are discussed in further detail 

below. The Rancho Cucamonga and Hesperia passenger stations would be constructed in 

already urban environments. Construction of passenger stations would not have direct effects 

on wildlife habitats, sensitive species, or critical habitats. 

1.2.2.1. Wildlife Habitats 

Many areas within the Caltrans right-of-way have been previously altered from suitable 

habitats by disturbance. The Caltrans right-of-way was generally mapped as Urban habitat. This 

habitat type consists almost entirely of developed areas such as highway, ramps, and other 

disturbed and unvegetated areas adjacent to I-15 (see Appendix A). The Project would retain 

these types of developed and disturbed surfaces, resulting in no change to the quality or 

function of the Urban habitat type. 

Construction of the Project would result in temporary and permanent impacts on wildlife 

habitat. Appendix A provides maps of habitat types along the study area, showing areas of 

temporary and permanent impacts on habitat types. 

Project construction would temporarily affect approximately 419 acres of native vegetation 

habitat not classified as Urban (Table 7). Construction staging and stockpiling, temporary 

ground disturbance (e.g., grading), and operation of heavy machinery may directly remove 

vegetation, smother it, or compact the soils such that vegetation can no longer persist in the 

short-term. Changes in vegetation may result in temporary loss of wildlife habitat or 

degradation of habitat functions. For some habitat types, temporary impacts on soil and 

vegetation permanently alter the habitat type to annual grassland. 

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Table 7. Temporary Impacts on Wildlife Habitat Types in All Project Sections 

CWHR Wildlife Habitat Type Habitat Codea 

Temporary Impact Area 

(acres) 

Alkali Desert Scrub ASC 3.93 

Annual Grassland AGS 16.47 

Barren BAR 3.98 

Chamise-Redshank Chaparral, Mixed Chaparral CRC, MCH 3.19 

Coastal Scrub CSC 15.14 

Desert Riparian DRI 9.04 

Desert Scrub DSC 167.55 

Desert Scrub, Desert Wash DSC, DSW 1.38 

Desert Wash DSW 43.59 

Eucalyptus EUC 0.04 

Joshua Tree JST 0.35 

Juniper JUN 1.94 

Mixed Chaparral MCH 128.14 

Riverine RIV 14.38 

Sagebrush SGB 8.08 

Urban URB 1,786.51 

Valley Foothill Riparian VRI 1.94 

Total 2,205.50 

a. CWHR codes are used on maps in Appendix A. 

Areas immediately adjacent to highways are routinely affected by tire and engine noise, trash, 

and maintenance activities. Occasionally road accidents travel into the adjacent landscape. 

These effects may result in changes in habitat structure and vegetation composition which can 

reduce habitat suitability for wildlife. Construction of the Project would result in temporary 

impacts on various habitat types (see Table 7). 

The time needed to recover Desert Riparian and Riverine habitat structure may be long and 

temporary impacts can be considered permanent impacts as a result; this would result in 

22 acres of additional permanent impacts on these sensitive habitats. Desert Scrub, Desert 

Wash, Joshua Tree and Juniper habitats are also slow to recover following disturbance, and 

restoration is very difficult. Temporary impacts of approximately 215 acres may be considered 

permanent where recovery would be long-term or impossible. 

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1.2.2.2. ESA-Listed Plant and Wildlife Species 

Construction activities may affect slender-horned spineflower and Santa Ana River woolly-star. 

Impacts on these could occur if populations are within the limits of construction. 

Table 8 shows the ESA-listed plant species that would be affected by construction of the 

Project; see Table 3 for preliminary effects determinations. 

Table 8. ESA-Listed Plant Species Likely to be Affected by Project Construction 

Common Name Scientific Name Status Under ESA 

Habitat Types Present in 

Study Area 

Slender-horned spineflower Dodecahema leptoceras Endangered Annual grassland, coastal scrub, 

mixed chaparral 

Santa Ana River woolly-star Eriastrum densifolium 

ssp. sanctorum 

Endangered Coastal scrub 

Construction activities could introduce or spread invasive plant species to areas with native 

vegetative communities. Ground disturbing activities and operation of construction equipment 

could result in seed dispersal as a result of soil movement. Changes in desert soil crust due to 

construction vehicles could loosen soils and facilitate seed dispersal. Weed species are adapted 

to soil disturbance and the abundant seeds are known to be readily transported to new 

locations by vehicles. 

Invasive, non-native plant species can displace native plant populations and reduce wildlife 

habitat quality. Control of invasive species should be identified as an essential element of 

construction practices, which would mitigate the risk of facilitating invasive species 

establishment. 

Construction activities such as vegetation clearing and excavation would expose soils and could 

result in increased wind erosion, creating construction-generated dust. Dust can affect 

vegetation over an area wider than the project footprint and can negatively affect plant 

physiology and productivity. 

Construction activities may affect sensitive wildlife including Arroyo toad, desert tortoise, least 

Bell’s vireo, southwestern-willow flycatcher, coastal California gnatcatcher, and San Bernardino 

Merriam’s kangaroo rat. Table 9 shows ESA-listed wildlife species likely to be affected by 

Project construction; see Table 3 for effect determinations. These effects would be considered 

adverse for arroyo toad, least Bell’s vireo, southwestern-willow flycatcher, and San Bernardino 

Merriam’s kangaroo rat and would require consultation with USFWS. 

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Table 9. ESA-Listed Wildlife Species Likely to be Affected by Project Construction 

Common Name Scientific Name Status Under ESA 

Habitat Types Present in 

Study Area 

Arroyo (southwestern) toad Anaxyrus californicus Endangered Annual grassland, coastal scrub, 

mixed chaparral, valley riparian 

Least Bell’s vireo Vireo bellii pusillus Endangered Desert riparian, valley riparian, 

desert wash 

Southwestern willow 

flycatcher 

Empidonax traillii extimus Endangered Valley riparian, desert wash 

Western yellow-billed cuckoo (Coccyzus americanus) Threatened Desert Riparian, Riverine, 

Valley Foothill Riparian 

Desert tortoise Gopherus agassizii Threatened Annual grassland, desert scrub, 

juniper, Joshua tree 

San Bernardino Merriam’s 

kangaroo rat 

Dipodomys merriami 

parvus 

Endangered Coastal scrub 

Coastal California gnatcatcher Polioptila californica 

californica 

Threatened Annual grassland, coastal scrub 

San Bernardino Merriam’s kangaroo rat and desert tortoise are assumed to be present in areas 

of suitable habitat. Desert tortoise is unlikely to occur within the project’s limits of disturbance

due to prior habitat deterioration associated with a transportation corridor (USFWS 2022c). 

. Construction-related activities could result in injury or mortality to animals present if 

construction equipment crushed or trapped them in their burrows or removed foraging habitat 

or habitat linkages. 

Construction-related effects on native vegetation communities would negatively affect foraging 

and nesting habitat for protected animal species. Construction activities (e.g., grubbing, 

grading, excavation, and driving off-road) could cause direct mortality of individuals of 

ESA-listed species, as heavy equipment could crush smaller animals. 

Indirect mortality could result from a decrease in the suitability and stability of burrows. 

Reduced movement in and across the study area would affect foraging and breeding and 

dispersal of these species. Construction activities could destroy active nests, burrows, or young 

if construction occurs during a species’ nesting or rearing season—potentially reducing the 

distribution of genetic material and resulting in long-term effects. 

The presence of construction crews may attract and subsidize foraging generalist species, such 

as ravens and coyotes, and in turn, may temporarily increase predation on species present in 

the study area. Ravens and coyotes are known to prey on juvenile mammals, reptiles, 

amphibians, and birds, and increased predator densities could result in increased mortality of 

individuals. 

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Construction noise could temporarily affect ESA-listed wildlife, such as limiting an individual’s 

ability to locate prey or habitat, causing physical damage to the individual’s auditory system, 

and causing adults to abandon nests or burrows. Increased noise effects wildlife by startling, 

reduced effectiveness of intraspecies communication, and masking the presence of predators. 

Pile-driving for bridge construction could create additional areas of auditory effects, including 

to avian species, migratory birds, and eagles as noise propagates in all directions including 

upward. Any work near or in water that creates noise could affect riparian and riverine habitats. 

Construction activities such as vegetation clearing and excavation would expose soils and could 

result in increased wind erosion, creating construction-generated dust. 

1.2.2.3. Effects on Migratory Birds and Eagles 

Cajon Pass is a known migratory flyway and project construction impacts may increase noise, 

causing migratory species protected under the MBTA to avoid the area. Construction could 

disturb the nesting and foraging of migratory birds. Construction activities (e.g., clearing, 

grading, excavation, pile driving, and loss of habitat elements such as cover) could affect 

migratory birds. 

Construction activities may disturb nesting eagles if nests are present within the affected area. 

Noise and construction activities may cause eagles to avoid foraging in the area. Golden eagles 

have been reported foraging in Cajon Canyon, but nesting sites are not known to be present, 

however noise and construction activities may cause raptors to avoid the area. 

If construction occurs during the breeding season (generally between March 1 and 

September 15), nesting migratory birds could be disturbed by construction activities and 

related noise. Cajon Pass and the Mojave River provide key habitat areas during migration for 

resting. Construction could disturb the nesting and foraging of migratory birds. Project 

construction impacts may increase noise, causing migratory species to avoid these key areas. 

Construction activities (e.g., clearing, grading, excavation, pile driving) and loss of habitat 

elements such as cover could affect migratory birds. As a result, birds may abandon nests, 

causing subsequent loss of eggs or young at active nests. 

Construction effects on migratory birds can be mitigated by implementation of timing that 

prohibits disturbance to vegetation during the nesting season and by overall reductions to 

disturbance through avoidance of disruptive activities. 

1.2.2.4. Designated Critical Habitat 

Critical habitat for arroyo toad, southwestern willow flycatcher, and San Bernardino Merriam’s 

kangaroo rat could be directly affected by construction activities. 

Construction would permanently affect designated critical habitat for the arroyo toad, San 

Bernardino Merriam’s kangaroo rat and southwestern willow flycatcher by converting habitat 

to transportation use and during construction activities. 

Rail line infrastructure would replace existing designated critical habitat for San Bernardino 

Merriam’s kangaroo rat, southwestern willow flycatcher, and arroyo toad with transportation 

use, thereby resulting in the permanent loss of the habitat. The effects on the species would be 

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limited to areas where suitable habitat is assumed to exist at the Mojave River, Cajon Canyon, 

Lytle Creek, and Cajon Wash. Temporary effects during construction would also occur in these 

areas. These effects would be considered adverse and would require a formal consultation with 

USFWS. 

Any work near or in-water could affect Riparian and Riverine habitat types directly, through 

hydrologic disruption or through decreased water quality by increased erosion and 

sedimentation. Changes in hydrology can alter vegetation causing shade reduction and loss of 

organic input. Blockages or changes to drainage patterns may result in effects on sensitive 

wildlife habitats and associated wildlife species. 

1.2.2.5. Habitat Connectivity and Wildlife Movement 

Linear transportation corridors such as I-15, are known to limit wildlife movement by blocking 

safe passage across landscapes. While the Project would develop rail within the I-15 median for 

most of the alignment the transportation corridor would be widened where rail would be 

developed adjacent to the side of existing I-15 (side-running), and where highway lanes or ramp 

locations would be altered (multiple locations). As such, the Project would result in additional 

constraints on wildlife movement by reinforcing the lack of safe passage locations across 

landscapes. 

Construction and operational noise could indirectly affect wildlife movement. Increased noise 

effects on wildlife could include startling, reducing effectiveness of intraspecies 

communication, and masking the presence of predators. Some wildlife species may alter their 

use or movement patterns during construction phases and then re-establish pre-project 

movement patterns and functions once temporary construction effects elapse. 

1.2.2.6. Hydrologic Changes 

Any construction work near or in-water could affect Riparian and Riverine habitat types through 

hydrologic disruption or through decreased water quality by increased erosion and 

sedimentation. Blockages or changes to drainage patterns may result in effects on wildlife 

habitats and associated wildlife species. 

Hydrologic changes can be reduced by minimizing the construction footprint in and near 

waterways. Implementing best management practices (BMPs) that address erosion and 

sediment control and monitoring those BMPs would further reduce potential effects on 

hydrology during construction. 

1.2.3. Operation of Build Alternative 

Project operation may directly affect ESA-listed wildlife species, migratory birds, and critical 

habitats. The Hesperia and Rancho Cucamonga stations would operate in developed, urban 

environments. Operational effects of the passenger stations would not have direct effects on 

wildlife habitats, ESA-listed species, or critical habitats. Operation of the stations would have no 

effect on migratory birds or eagles. Indirect effects of station operations, such as subsidized 

predation are possible. 

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1.2.3.1. Wildlife Habitat 

Ongoing operations and maintenance activities can directly or indirectly affect wildlife habitats 

that support sensitive species. Effects on ESA-listed plants could include mortality from 

incidental trampling or crushing caused by activities related to the maintenance of the rail. 

The Project may result in permanent impacts on vegetation communities that serve as wildlife 

habitat. Appendix A provides maps of habitat types in the study area, showing areas of 

permanent impact on habitat types along the alignment. As stated, many areas within the 

Caltrans right-of-way have been altered from natural vegetation community composition by 

previous disturbance and on-going disturbance; these areas are generally mapped as Urban 

habitats. The Build Alternative would retain these types of developed and disturbed surfaces, 

resulting in no change to the quality or function of the Urban habitat types. 

As shown in Table 10, Approximately 64 acres of native vegetation habitat types would be 

permanently converted to transportation uses by the Project. Permanent impacts occur in a 

wide variety of habitat types; most of the area of permanent impact would be to Desert Scrub 

(37 acres). Where Desert Scrub is suitable, desert tortoise may be present. 

Table 10. Permanent Impacts on Wildlife Habitat, by Habitat Types 

CWHR Wildlife Habitat Type Habitat Code 

Permanent Impact Area 

(acres) 

Alkali Desert Scrub ASC 0.54 

Annual Grassland AGS 2.40 

Barren BAR 0.63 

Coastal Scrub CSC 0.18 

Desert Riparian DRI 0.95 

Desert Scrub DSC 36.62 

Desert Wash DSW 0.60 

Juniper JUN 0.88 

Mixed Chaparral MCH 6.45 

Riverine RIV 0.73 

Sagebrush SGB 13.58 

Total 63.93 

1.2.3.2. ESA-Listed Plant and Wildlife Species 

Table 11 shows the ESA-listed plant species that would be affected by the Project. Creation of 

new ignition sources by the Project could result in indirect effects on biological resources 

through increased frequency of wildland fire. The Project would construct new powerlines on 

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catenary structures to provide traction power to power trains in a known high wind area. The 

project design would include automatic power shutoff and other safety features that would 

work to cut power and prevent powerline failures from becoming ignition sources. 

Landscaping and maintenance in the corridor during operation would be focused on avoiding 

invasive seed dispersal, controlling existing invasive populations, and restoring areas with 

native vegetation following invasive species removals. 

Table 11. ESA-Listed Plant Species Likely to be Affected by Project Operation 

Common Name Scientific Name Status Under ESA 

Suitable Habitat Present in 

Study Area 

Slender-horned spineflower Dodecahema leptoceras Endangered Annual grassland, mixed 

chaparral, coastal scrub 

Santa Ana River woolly-star Eriastrum densifolium 

ssp. sanctorum 

Endangered coastal scrub 

Table 12 shows the ESA-listed wildlife species potentially affected by Project operations. The 

Project would add trains traveling up to 140 mph to the I-15 corridor, which would increase the 

likelihood of animal strikes along the corridor, particularly in areas where wildlife is abundant. 

As a result, the Project would likely directly increase mortality of individuals of special status 

species. For all at-grade portions of the alignment, exclusion fencing would be constructed 

parallel to the rail line for safety. However, this safety step also serves to trap animals that may 

have gained access to the highway and/or rail corridor, potentially increasing the risk of wildlife 

strikes. By converting the highway median from a natural surface to impervious surface, the 

Project may remove access to resting habitat for wildlife attempting to cross I-15 and the 

project corridor possibly causing increased wildlife mortality. 

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Table 12. ESA-Listed Wildlife Species which May be Affected by Project Operation 

Common Name Scientific Name Status Under ESA 

Habitats Present in 

Study Area 

Arroyo (southwestern) toad Anaxyrus californicus Endangered Annual grassland, coastal scrub, 

chemise-redshank, mixed 

chaparral, valley riparian 

Least Bell’s vireo Vireo bellii pusillus Endangered Desert riparian, valley riparian, 

desert wash 

Southwestern willow 

flycatcher 

Empidonax traillii extimus Endangered Valley riparian, desert riparian 

Western yellow-billed cuckoo Coccyzus americanus 

occidentalis 

Threatened Desert riparian, valley foothill 

riparian 

Desert tortoise Gopherus agassizii Threatened Annual grassland, desert scrub, 

desert wash, juniper, Joshua 

tree 

San Bernardino Merriam’s 

kangaroo rat 

Dipodomys merriami 

parvus 

Endangered Coastal scrub 

Coastal California gnatcatcher Polioptila californica 

californica 

Threatened Coastal scrub, annual 

grassland, mixed chaparral 

During operations, subsidized predation could occur due to human activities that may 

inadvertently provide food and/or shelter to generalist predators. The Project’s catenary

system could add perch locations that may be used by avian predators for nesting, such as 

ravens, which may support population increases and thus increase predation of special status 

species. Train strikes of avian and terrestrial species could increase supply of carrion to 

generalist predators and result in supporting larger populations. Increased predator numbers 

may add predation pressure to ESA-listed species in the area, such as desert tortoise. 

During operations subsidized predation can be avoided through planned design that has 

avoided or eliminated perches and potential nesting sites for generalist predators. Maintenance 

of the railway and passenger stations, including keeping trash picked up and implementing 

strong, wind-proof, covered trash collection areas is important to reduce subsidized predation. 

A regular maintenance program that identifies, implements, and reinforces good housekeeping 

would mitigate the potential indirect effect of human subsidized predation. Identified perching 

and nesting locations would be modified to make them no longer suitable. 

Even though the existing highway generates considerable noise, operation of the railway was 

not shown to increase noise levels above the existing highway noise along the alignment (CrossSpectrum Acoustics 2022). For median-running rail, operational noise would generally occur 

within the extent of the existing developed highway. No noise modeling was performed for 

wildlife receptors, however, wherever noise sensitive species are present in the corridor, these 

species could be expected to alter behavior due to the additional operational noise from trains. 

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Sensitive species may startle at passing train noise or completely avoid the area if the noise 

added by trains exceeds tolerance thresholds. Noise avoidance results in reduced habitat 

suitability and/or habitat area for species and may reduce the ability to migrate. 

1.2.3.3. Designated Critical Habitat 

Operation of the rail line would occur across and adjacent to designated critical habitat for 

arroyo toad, San Bernardino Merriam’s kangaroo rat, and southwestern willow flycatcher. 

Operation of the rail line would not directly affect adjacent designated critical habitat; however 

indirect effects are possible. 

Operation of the railway was shown to not increase noise levels above the existing highway 

noise along the alignment (Cross-Spectrum Acoustics 2022).For median-running rail, 

operational noise would generally occur within the extent of the existing developed highway. . 

The portions of the project which align within the existing highway median are not expected to 

contribute to potential fire starts due to the hardened surfaces and location of the rail within 

the median of the existing highway. The Project would construct new powerlines on catenary 

structures to provide traction power to power trains in a known high wind area. The project 

design would include automatic power shutoff and other safety features that would work to cut 

power and prevent powerline failures from becoming ignition sources. 

1.2.3.4. Effects on Migratory Birds 

Operational effects on migratory birds could be direct if avian species use new structures in the 

rail corridor for nesting or foraging and bird strikes occur. Indirect impacts may occur to 

migratory birds in areas adjacent to the corridor due to increased noise, causing migratory 

species to avoid these areas. As stated, an increase in noise though train operations may result 

in exceedance of noise tolerance thresholds, birds may avoid adjacent areas causing a 

reduction in suitable nesting areas. 

Operation of HSR could result in mortality through collisions. Collisions could occur to any 

wildlife in the path of the train and would be of concern for ESA-listed species and migratory 

birds. A study recording bird-high-speed train collisions demonstrated an average mortality rate 

of 60 birds per kilometer (about 96 birds per mile) per year for all bird species when operation 

frequency was 53 trains per day (García de la Morena 2017). The study also showed that 

approximately 38 percent of bird crossings were of birds resting on some element of the 

infrastructure moments prior to arrival of the train. The study was based on filming and only 

included daylight hours, so an estimate of strikes during nighttime was not made. For the 

Project, it is not known if the location of proposed rail infrastructure in the highway median 

would attract birds resting while attempting to cross the highway, thus increasing the number 

of birds within striking distance, or if the highway itself would reduce the likelihood of perching 

on rail infrastructure. Based on the 2017 study, it appears bird strike mortalities are likely; 

however, the number of strikes may differ significantly in magnitude from the study due to the 

different environmental, infrastructure, and operating conditions of the Project from the 

study’s conditions.

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1.2.3.5. Habitat Connectivity and Wildlife Movement 

Linear transportation corridors are known to limit wildlife movement by blocking safe passage 

across landscapes. I-15 is an existing barrier to local and regional wildlife movement across the 

landscape throughout the proposed project alignment. The barrier is hazardous and somewhat 

pervious as wildlife are known to successfully cross at times. 

Because the rail line is aligned with I-15, the Project would widen this existing linear 

transportation corridor at those portions that would lie outside the I-15 median, and in 

locations where the highway lanes would be widened to accommodate median-running rail. 

Widening the transportation corridor would reinforce the blockage of wildlife movement in 

areas where no suitable crossing was present. Fencing of the median for HSR safety would 

further reinforce the corridor to crossing and would make I-15 impossible for terrestrial species 

to cross safely. 

Project design includes lengthening existing I-15 culverts in the same locations, which would 

allow culverts to continue to function as wildlife crossings, if the additional length did not 

preclude this. 

Maintenance activities are expected to be dispersed over time and location and are not 

expected to be of an intensity or duration to result in substantial impacts on wildlife movement 

or habitat use. Landscaping maintenance would be focused on avoiding invasive seed dispersal, 

controlling existing invasive plant populations where present, and restoring areas with native 

vegetation to reduce potential impacts of invasive species to wildlife and native plant 

communities. 

1.2.4. Cumulative Effects 

The Project, in combination with other past, present, and reasonably foreseeable future 

actions, would convert undeveloped areas to developed ones, resulting in habitat loss, 

additional fragmentation in some locations, and potentially associated loss of common and 

special status plant and animal species. 

The Project would potentially facilitate development pressure in the Apple Valley planning area 

(City of Apple Valley) and the Desert Planning area (City of Victorville) surrounding the final 

5 miles of the alignment and project terminus, where demand for commuter and recreational 

access to HSR transportation would increase as result of a new transportation element 

provided by the Project. The Apple Valley and Desert planning areas are currently largely 

undeveloped, and their development would result in loss of habitat supporting common and 

ESA-listed wildlife species. 

The town of Apple Valley is developing a multispecies HCP to guide development at a landscape 

level for the Apple Valley planning area in the vicinity of the project terminus. However, there 

does not appear to be a parallel planning effort for the Desert planning area of Victorville. 

Planning elements could be identified to mitigate cumulative effects, for example, by 

identifying conservation areas and protecting viable habitat linkages (Apple Valley 2022). 

Combined with the effects of future development, effects of the Project may further reduce the 

suitability of remaining habitat to support listed species San Bernardino Merriam’s kangaroo 

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rat, coastal California gnatcatcher, slender-horned spineflower, and Santa Ana River woolly-star 

in the vicinity of Section 3, Greater Los Angeles. In this area, the North Fontana Conservation 

Program has identified conservation actions that work to protect and mitigate development on 

Riversidean Alluvial Fan Sage Scrub thereby providing support to these ESA-listed species and 

associated habitats. Future development in the North Fontana area would be required to 

comply with the action plan and implementation plan developed under the conservation 

program, thus mitigating some cumulative effects. 

Implementation and development of conservation and mitigation approaches could reduce 

cumulative effects on habitats and plant and animal species. Preserving and conserving wildlife 

habitats and other biological resources would help to reduce cumulative effects on biological 

resources. 

1.2.5. Avoidance, Minimization, and Mitigation Measures 

As stated, FRA and USFWS are required to consult under Section 7 of the ESA. Final mitigation 

and compensation strategies would be determined during the consultation and will be 

documented by USFWS through a Biological Opinion along with an Incidental Take Permit for 

ESA-listed species. The applicant would also coordinate with FRA for appropriate mitigation 

strategies under the MBTA and the BGEPA and Executive Orders 13112 and 13751. 

Compensation for minimized unavoidable impacts could be provided as onsite restoration 

and/or creation, offsite restoration, acquisition of mitigation credits, acquisition and protection 

of conservation lands, or a combination of these methods. 

Practicable measures to avoid impacts on threatened and endangered species and their critical 

habitats, such as those described below, would be implemented by the Project. In areas where 

unavoidable impacts may occur, efforts would be made to minimize those impacts. Following 

implementation of avoidance and minimization measures, the Proposed Action would employ 

compensation measures to offset any unavoidable, minimized, impacts that occur. 

The following are mitigation measures for the Proposed Action. . General measures are 

followed by additional measures for specific species. 

A detailed Habitat Restoration Plan discussing the details of soil and vegetation restoration to 

be implemented following temporary construction disturbance at specific areas, along with a 

detailed a Translocate Plans for San Bernardino Kangaroo Rat are provided under separate 

cover. 

1.2.5.1. General Measures 

Areas of Concern During Construction 

Biologists shall be present for construction activities along the following portions of the Project 

alignment: 

• Mojave Desert vicinity: From the northern-most Project extent, continuing south to the I-15 

Bridge over D/E Street in Victorville 

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– Focusing on protection of southwestern willow flycatcher, monarch butterfly, 

western yellow-billed cuckoo, least Bell’s vireo, and critical habitat for 

southwestern willow flycatcher. 

• Cajon Canyon and Cajon Summit vicinity: From I-15 at Oak Hill Road to I-15 at Hall Ranch 

Road 

– Focusing on protection of southwestern willow flycatcher, least Bell’s vireo, 

monarch butterfly, arroyo toad, and critical habitat for arroyo toad. 

• Cajon Wash and Lytle Creek vicinity: From I-15 at Hall Ranch Road to I-15 at Summit Avenue 

– Focusing on protection of San Bernardino Merriam’s kangaroo rat, coastal 

California gnatcatcher, ESA-listed plants, monarch butterfly, and critical habitat 

for San Bernardino Merriam’s kangaroo rat. 

Note that monarch butterfly, a candidate species for listing under ESA, may be present in any 

portion of the Project area during nine months of the year. 

No biologist is required during construction along portions of the alignment not listed above—

for example, in urban areas of Rancho Cucamonga, Hesperia, and Victorville—although the 

Applicant and its contractors may choose to utilize resource monitors/biological monitors at 

their discretion in these areas to ensure environmental compliance. 

Avian Avoidance - Exclusion Areas and Timing 

Certain types of construction activities are not to be commenced during bird breeding season at 

three separate locations along the alignment. The types of construction activities regulated are 

pile driving and ground disturbance (defined below). This avoidance mitigation measure does 

not apply to other construction activities or other locations. 

Three separate locations of Avian Avoidance Exclusion Areas are as follows: 

• Area 1. Mojave River 

• Area 2. Cajon Wash 

• Area 3. Lytle Creek 

Pile driving and ground disturbance activities are prohibited in the Avian Avoidance Exclusion 

Areas during closure dates, unless the work is initiated prior to the start of the closure period. 

Project-related ground disturbance is defined as: 

• Vegetation removal, including clearing and grubbing of vegetation, 

• Site preparation including grading and establishment of construction access, or 

• Grading, earth moving, stockpiling materials, excavation, and filling activities. 

Table 13 summarizes the closure dates for the three Avian Avoidance Exclusion Areas. 

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Table 13. Avian Avoidance Exclusion Areas and Closure Dates 

Location 

Closure Dates 

From To 

Area 1. Mojave River Crossing March 15 September 30 

Area 2. Cajon Wash February 15 September 30 

Area 3. Lytle Creek February 15 September 30 

Conduct Mandatory Environmental Awareness Training Program 

All Project staff, including Applicant, contractors, operators, consultants, field personnel, and 

subcontractors, shall attend a mandatory environmental awareness training program. The 

program will be developed and presented by knowledgeable biologists. 

The curriculum shall cover the following, at a minimum: 

• Awareness information for each ESA-listed species potentially present and designated 

critical habitats in the Project area 

• The legal protection for each ESA-listed species, critical habitats, and the definition of “take” 

for listed species 

• Measures to protect ESA-listed species during construction 

• Review of the Project’s environmental commitments, restoration steps, and mitigation 

requirements 

• Explanation of the reasoning behind the restrictions on the construction, where restrictions 

exist 

• Importance of avoiding ground-disturbing activities outside the designated work areas, 

closing construction gates, and visually surveying designated work zones prior to moving 

equipment 

• Requirements for ground and general areas inspection prior to moving vehicles and 

equipment 

• Explanation of the problem of generalist predators, such as common ravens (Corvus corax) 

• Explanation of the importance of keeping construction areas free from trash and litter and 

avoiding subsidizing generalist predators 

• Penalties for violation of federal and state environmental laws 

Training shall be documented, including names of trainees and dates of completion. All trained 

workers will be given an identifying sticker to be worn on site. 

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Plan for and Conduct Biological Monitoring during Construction 

At least 60 days prior to the start of Project-related ground disturbance that would occur within 

200 feet of any occupied ESA-listed habitat or within any suitable habitat within designated 

critical habitat area, a written Biological Monitoring Plan (Plan) shall be developed for approval 

by USFWS. 

The Plan shall discuss the type, locations, and timing of physical disturbance: (1) within 400 feet 

of any occupied ESA-listed species habitat, or (2) within suitable habitat within all designated 

critical habitat areas. 

The Plan will identify appropriate monitoring and reporting needs, including responsibilities, 

timing, and monitoring activities, and will identify coordination requirements, safety 

requirements, and communications, including points of contact. The Plan shall be implemented 

during construction to ensure compliance with environmental commitments and will focus on 

commitments under the ESA. 

Reporting 

No more than 120 days after the completion of construction, the biologist(s) shall prepare a 

monitoring, restoration, and mitigation report for submission to USFWS for any construction 

areas: (1) within 400 feet of any occupied ESA-listed species habitat, or (2) within suitable 

habitat within all designated critical habitat areas. The report will include the results of 

construction monitoring, photographs, and the type and locations of installed mitigation and 

restoration measures. 

Photographs 

Pre- and post-construction photographs shall be taken to document habitat conditions and 

alterations within the limits of disturbance during construction activities. Photographs will be 

dated, their locations recorded, and will be stored in a manner that will allow access for 

reporting purposes. 

Designated Work Areas 

In areas adjacent to sensitive resources, the contractor shall restrict all work to designated 

work areas through the use of visible demarcation. 

The following are locations of sensitive resources: 

• Mojave Desert vicinity: From the northern-most Project extent, continuing south to the I-15 

Bridge over D/E Street in Victorville 

• Cajon Canyon and Cajon Summit vicinity: From I-15 at Oak Hill Road to I-15 at Hall Ranch 

Road 

• Cajon Wash and Lytle Creek vicinity: From I-15 at Hall Ranch Road to I-15 at Summit Avenue 

The contractor shall avoid any unauthorized disturbance of native vegetation and sensitive 

resources outside the designated work area. Remnant habitat and existing stands of native 

vegetation will be identified and protected wherever possible. 

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During construction, the biologist, or their representative, shall inspect the visible demarcation 

and shall help ensure that construction equipment, vehicles, and associated activities remain 

within designated construction work areas. 

Noxious Weed Management During Construction 

A noxious weed survey shall be performed prior to ground-disturbing activities. During and 

following construction, the contractor shall avoid the introduction or spread of noxious weeds 

by performing weekly inspections and weed removal/control. 

Avoid Injury to Wildlife 

Supplies, equipment, and/or construction excavations where wildlife could hide (e.g., materials 

stockpiles, equipment in staging areas, and under vehicles) shall be inspected by all 

construction crew members prior to moving or working on or with them to avoid killing or 

injuring wildlife. If wildlife is detected, the biologist shall be contacted. 

Preserve Biological Material 

The contractor and Applicant shall preserve any dead biological material encountered related 

to endangered species in the best possible state for later analysis. Preservation may include 

chilling and general protection from disturbance. 

Prepare and Implement a Temporary Erosion and Sediment Control Plan 

The contractor shall prepare and implement a Temporary Erosion and Sediment Control Plan 

that identifies best management practices (BMPs) best suited for site conditions. The plan shall 

meet applicable Caltrans standards. 

Implement Spill Prevention, Control, and Countermeasures Plan 

The contractor shall develop and implement a Spill Prevention, Control, and Countermeasures 

Plan for construction activities. The potential for chemical spills or releases of contaminants, 

including any non-stormwater discharge to drainage channels, shall be managed and the risk 

reduced. If a spill occurs, cleanup, containment, and response measures shall be implemented. 

Any accidental spills will be immediately contained and reported to the California Office of 

Emergency Services (1-800-852-7650) and the National Response Center (1-800-424-8802). 

No Storage of Construction Equipment or Materials within the 100-Year Floodplain 

The contractor shall not store construction equipment, chemicals, fuels, or lubricants within the 

100-year floodplain of any water feature. 

Equipment Maintenance and Refueling only in Designated Areas 

All equipment maintenance and dispensing of fuel, oil, coolant, or any other such activities will 

be restricted to the designated staging areas outside of the Mojave River floodplain, Cajon 

Wash, and Lytle Creek to prevent the release of hazardous substances into these sensitive 

areas. 

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Fugitive Dust Control Plan 

The contractor shall develop and implement a Fugitive Dust Control Plan that includes, at a 

minimum, the following: 

• Reduce nonessential earth-moving activity under high-wind conditions when visible dusting 

occurs from surfaces due to wind erosion. 

• Water shall be used for stabilization of surfaces for fugitive dust control within 400 feet of 

areas occupied by ESA-listed species, or within suitable habitat within designated critical 

habitat areas. 

• Periodic watering for short-term stabilization of disturbed surface area. 

• Prevent track-out onto paved surfaces and clean up any tracked materials immediately. 

• Stabilize graded site surfaces upon completion of grading when subsequent development is 

delayed or expected to be delayed more than 30 days, except when such a delay is due to 

precipitation that dampens the disturbed surface sufficiently to eliminate visible fugitive 

dust emissions. 

Prevent Erosion and Sedimentation 

Applicant shall employ permanent stabilization measures upon completion of construction 

along washes and in other areas of potential erosion. 

Minimize Impacts on Water Availability 

Water will be obtained from existing commercially available water sources during construction. 

No new groundwater wells or surface water impoundments will be developed without federal, 

state, and local permits as appropriate and legally required. 

Drainage Systems Design 

Existing stormwater systems will be designed or redesigned to accommodate runoff from 

impervious surfaces. Drainage facilities shall detain flows and shall not contribute to additional 

flows in rivers, streams, and washes. 

Nesting Sites 

All new utility lines and ancillary structures associated with the Project shall be designed in a 

manner that will reduce the likelihood of nesting, especially by common ravens. 

Incorporate Site-Specific Permanent Water Quality Treatment Devices 

Permanent water quality treatment devices that comply with state and local requirements, as 

applicable, will be installed to meet water quality objectives. 

Construction Noise and Vibration Control Measures 

The contractor shall employ noise control measures to reduce noise from construction 

including: 

• Use equipment with enclosed engines and/or high-performance mufflers. 

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• Locate stationary construction equipment as far as possible from noise-sensitive sites. 

• Construct noise barriers, such as temporary walls or piles of excavated material, between 

noisy activities and noise-sensitive receivers. 

• Route truck traffic along roadways that will cause the least disturbance to species. 

• Avoid impact pile driving wherever possible. Use drilled piles or sonic/vibratory pile driver 

wherever possible. If impact pile drivers must be used near noise-sensitive receptors, 

implement a slow start and limit activity to daylight hours. 

Implement Litter-Control Program 

The contractor shall implement a litter-control program during construction to avoid subsidizing 

(feeding) generalized scavengers, such as common ravens. The program will include: 

• Use of covered, common-raven-proof trash receptacles 

• Daily removal of trash from the trash receptacles 

• Daily site inspections 

• Proper disposal of trash in a designated solid waste disposal facility 

Precautions will also be taken to prevent trash from blowing out of construction vehicles. 

Implement Housekeeping to Deter Opportunist Predators 

To mitigate subsidized predation, operational standards will be planned and implemented to 

maintain railway and stations free of food and habitat elements that facilitate opportunist 

predators. 

Prohibited Items and Feeding of Wildlife 

Feeding of wildlife shall not be allowed. No pets or firearms will be allowed in the construction 

area. 

Maintain Existing Wildlife Crossings 

New culverts, bridges, and viaducts shall align with any existing I-15 structures to maintain a 

continuous wildlife crossing corridor. Where the alignment of new culvert, bridges, or viaduct 

would deviate from alignment with existing I-15 structures, the Applicant shall design and 

install appropriately sized crossing structures at appropriate intervals to allow for terrestrial 

wildlife to pass under the proposed alignment. 

Avian Species Preconstruction Surveys 

Surveys for the presence of suitable habitat for nesting avian species (least Bell’s vireo, western 

yellow-billed cuckoo, and southwestern willow flycatcher) following standard protocols 

(Halterman et al. 2015; Sogge et al. 2010; USFWS 2001) at locations of potentially suitable 

habitat within the temporary and permanent limits of disturbance (LOD) shall be conducted 

prior to the start of construction. Surveys by biologists that meet USFWS’s minimum 

qualifications (USFWS 2019) for the presence of suitable habitat for coastal scrub nesting avian 

species (coastal California gnatcatcher) at locations of potentially suitable habitat shall be 

32 BIOLOGICAL RESOURCES TECHNICAL REPORT, OCTOBER 2022 
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conducted prior to the start of construction. Coordination with USFWS is required on the result 

of the surveys. 

Native Plant Community Restoration Plans 

The Applicant shall develop and implement Restoration Plans to restore areas of native 

vegetation that are temporarily disturbed by construction. Within Caltrans right-of-way, 

restoration shall follow Caltrans requirements. Within Caltrans right-of-way that is also within 

designated critical habitat, restoration will include habitat structure consideration of each 

species. Initiation of restoration will occur within one year of the completion of construction at 

any location along the alignment, during the appropriate seasonal window. Replanting will not 

be delayed. 

The Restoration Plan(s) shall address: 

• Restoration of site topography to preconstruction contours 

• Soils amendments and ameliorate soil compaction 

• Soil stabilization by compost, mulch, erosion blankets, or other as appropriate 

Stockpile Native Topsoil for Reuse in Restoration 

The contractor shall stockpile and protect removed native topsoil and shall use the stockpiled 

topsoil in restoration and landscaped areas. Areas from where topsoil is recovered shall be free 

from invasive plant species. 

Irrigation 

In consultation with the Caltrans District Landscape Architect, permanent or temporary 

irrigation systems to supply water to replacement landscape plantings shall be developed and 

implemented. 

Minimize Negative Effects of Nighttime Operational Lighting 

Nighttime lighting at passenger stations and along the rail alignment shall incorporate 

minimized light intensity, duration, and distribution and will utilize wildlife- and insect-sensitive 

spectrum lighting to reduce the negative effects of artificial nighttime lighting to sensitive 

species. Passenger stations shall incorporate light and glare screening measures—for example, 

use downward-cast lighting—and shall use motion sensor lighting, where appropriate. 

Remove Track-Killed Animals 

The Applicant will promptly remove all track-killed animals along the operating rail line to 

reduce adverse effects associated with food subsidies to generalist predators, such as common 

ravens. 

Remove Common Raven Nests 

The applicant shall annually monitor catenary and ancillary structures, power poles, auxiliary 

buildings, passenger stations, and parking areas to identify and remove common raven nests 

outside of the nesting season. Once raven nesting sites are identified, actions will be taken to 

block the site from raven reuse. In coordination with USFWS, adaptive management may be 

undertaken if the initial measures are unsuccessful to remove common raven nests. 

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Operations of Passenger Stations 

To mitigate potential subsidized predation, the Applicant shall plan and implement operational 

standards for maintaining railway and passenger stations to not support generalist predators. 

Stations and other operations areas shall always be free of food sources and will eliminate 

habitat support elements that facilitate opportunist predators. 

Invasive Plant Species Control During Operations 

Following the completion of construction activities, the Applicant shall develop an Invasive 

Plant Species Monitoring and Control Plan for review and approval by USFWS. Invasive plant 

species in the temporary disturbed areas and operational areas shall be monitored: 

• Monthly from January through June for two growing seasons following construction 

Control may consist of manual or herbicide control methods. Note that herbicide use in riparian 

areas and waters of the state is regulated. Herbicide use may be curtailed or avoided in desert 

tortoise habitat areas. 

1.2.5.2. Arroyo Toad 

AT-1. Arroyo Toad Preconstruction Surveys 

Surveys for the presence of suitable habitat for arroyo toad will be conducted by qualified 

biologists prior to the start of construction. Coordination with USFWS prior to implementation 

of any survey is required. 

Presence/absence surveys will be conducted at all locations identified to have suitable habitat 

prior to the start of construction. Depending upon survey findings, additional protective 

measures during construction may be required. 

Survey procedures will be consistent with survey protocols for arroyo toad (USFWS 1999a). To 

be reasonably confident that arroyo toads are not present at a site, at least six (6) surveys must 

be conducted with at least 7 days between surveys. Surveys will be conducted during the 

breeding season, which generally occurs from March 15 through July 1. Extreme weather 

conditions can cause variations in the breeding season; these conditions should be fully 

considered when developing a schedule of surveys. 

1.2.5.3.   


SBKR-1. San Bernardino Kangaroo Rat Restricted Work Areas 

In collaboration with USFWS and prior to the start of any ground disturbance, the biologist shall 

identify areas within the construction temporary and permanent limits of disturbance (LOD) 

that may support San Bernardino Merriam’s kangaroo rat. These areas shall be called “SBKR 

restricted work areas.” and most likely located along the Project alignment between the vicinity 

of Hall Ranch Road to the vicinity of Summit Avenue and include Cajon Wash. Areas of existing 

infrastructure and areas lying between I-15 highway lanes (median) in these vicinities would not 

be included in restricted work areas. Coordination with and approval by USFWS shall occur to 

identify and refine the geographical boundary of the SBKR restricted work areas. 

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SBKR-2. Conduct San Bernardino Merriam’s Kangaroo Rat Preconstruction Surveys 

The contractor or Applicant shall implement surveys for San Bernardino Merriam’s kangaroo rat

prior to initiation of ground-disturbing activities in the SBKR restricted work areas. Coordination 

with USFWS shall occur prior to implementation of any surveys for San Bernardino Merriam’s 

kangaroo rat. Surveyors shall obtain ESA Section 10(a) permits, as necessary. Areas to be 

surveyed and results of surveys will be coordinated with USFWS. 

SBKR-3. Construction Monitoring and Reporting Requirements for SBKR Restricted Work 

Areas 

For the duration of construction work within the SBKR restricted work area, the biologist(s) 

shall: 

• Review the previous week’s construction activities and the upcoming week’s construction 

activities to determine if there are areas that need additional inspection, fencing, or 

monitoring. 

• Inspect the San Bernardino Merriam’s kangaroo rat barrier fencing daily during active 

ground disturbance. 

• Inspect San Bernardino Merriam’s kangaroo rat barrier fencing weekly during any pause in 

construction of greater than 1 week. 

• Search the construction footprint for any kangaroo rat sign early in the morning and prior to 

any ground-disturbing activities. 

• Contact USFWS immediately if kangaroo rat sign is detected inside the barrier fencing. 

• Provide a weekly written report of construction monitoring activities and findings to USFWS 

within 4 business days following the end of each week during ground-disturbing 

construction within the SBKR restricted work area. 

SBKR-4. Install and Maintain San Bernardino Merriam’s Kangaroo Rat Barrier Fencing 

Within any portion of the SBKR restricted work area and prior to initiating ground-disturbing 

activities, San Bernardino Merriam’s kangaroo rat barrier fencing shall be installed between the 

construction activities and the surrounding area. 

• San Bernardino Merriam’s kangaroo rat barrier fencing will be constructed. San Bernardino 

Merriam’s kangaroo rats can be excluded with fencing suitable for effective small mammal 

exclusion that uses anti-climb technology, 30 to 36 inches high above ground with the 

bottom buried at least 12 inches deep with a 6-inch apron lying at 12 inches deep at a right 

angle. 

• No gaps greater than 0.5 inch will be allowed. 

• The Biologist or the biologist’s representative will be present when the fence is installed to

ensure that no burrows or burrow entrances are covered by the apron of the barrier fence. 

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• The construction monitor will check the temporary barrier fencing at the close of each 

workday to ensure it is in place and properly maintained. 

• Fence gaps greater than 0.5 inch will be repaired within 24 hours of detection. 

SBKR-5. Preconstruction Trapping 

Prior to ground disturbance, the Biologist(s) shall conduct preconstruction trapping of San 

Bernardino Kangaroo rats inside exclusion fenced areas. Trapping will be conducted at each 

location until no San Bernardino Merriam’s kangaroo rats are trapped for two consecutive 

nights. Initial trapping is required to be performed on the evening of the first day on which the 

barrier fence installation is complete. 

SBKR-6. Trapped San Bernardino Merriam’s Kangaroo Rat Housing and Release 

The biologist(s) shall house and release all captured San Bernardino Merriam’s kangaroo rats as 

soon as possible following trapping. The captured San Bernardino Merriam’s kangaroo rats will 

be housed in suitable facilities until the released. The protocol for housing trapped San 

Bernardino Merriam’s kangaroo rats will follow the holding/animal care requirements. 

Captured San Bernardino Merriam’s kangaroo rats will be translocated by soft-release into 

appropriate receiving habitat. 

1.2.5.4. Desert Tortoise 

DT-1. Desert Tortoise Potential or Actual Presence and Response 

Desert tortoise is not likely to occur within the construction area; thus, preconstruction surveys 

are not required at this time. If desert tortoise sign, burrows, or individuals are determined to 

be, or possibly be, present in areas of ground disturbance, then USFWS shall be notified 

immediately. 

In any situation where a desert tortoise places itself in danger (e.g., it enters a work area), 

immediate action will be undertaken protect the animal and the USFWS will be contacted for 

additional guidance. Work in the vicinity that could injure or kill the animal will immediately 

cease. The animal will be observed until it is moved with USFWS approval from harm’s way.

DT-2. Design and Install Suitable Culverts 

Where culverts are used, the Applicant shall design and install desert tortoise-suitable culverts. 

Box culverts must be at least 3 feet on a side, and pipe culverts must be at least 3 feet in 

diameter. Box culverts are recommended over pipe culverts because desert tortoises are less 

likely to use box culverts as burrows. If a new culvert is to be tied to an existing culvert under 

I-15, the Applicant, with approval from USFWS, may forego these specifications if they are 

incompatible with the existing culverts. 

DT-3. Refer to USFWS Regarding Desert Tortoise 

Construction crew members will refer all issues regarding the desert tortoise to the ABUSFWS 

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DT-4. Provide Rock-Slope Protections 

Placement and construction of rock-slope protections shall require the interstitial spaces within 

rock-slope protection to be filled with substrate to prevent trapping of desert tortoises. 

1.2.5.5. ESA-Listed Plant Species Protection 

P-1. ESA-Listed Plants Preconstruction Surveys 

Qualified botanists will conduct preconstruction surveys within suitable habitat for ESA-listed 

plant species prior to any ground disturbing activities. 

P-2. Protect ESA-Listed Plant Populations 

Prior to initiating ground-disturbing activities, temporary construction fencing shall be placed 

around all ESA-listed plant species that occur within the temporary construction areas to 

demarcate locations. When ESA-listed plants are observed within temporary construction 

areas, avoidance and minimization measures shall be applied. Exclusionary areas shall be signed 

for avoidance by construction equipment and personnel. Depending on the proximity of the 

ESA-listed plant populations to the construction work area, the plant populations shall be 

monitored during and following construction to avoid adverse effects. 

P-3. Avoid Known Special-Status Plant Populations 

To the extent possible, the Project shall completely avoid areas with ESA-listed plant 

populations by designing bridge piers outside such areas. 

1.2.5.6. Monarch Butterfly 

MB-1. Provide and Support Pollinator and Nectary Sources 

Pollinator plants and milkweed species supporting monarch butterflies must be included in 

plans for restoration and landscape areas. 

1.2.5.7. Nesting Migratory Birds 

MBTA-1. Coordinate Construction Timing to protect Migratory Birds 

In areas of suitable nesting habitats at the Mojave River, Lytle Creek, Cajon Wash, Cajon 

Canyon, and Cajon Summit vegetation disturbance during construction would be scheduled to 

avoid migratory bird nesting season, from February 15 to September 30, to avoid take under 

the MBTA. 

BIOLOGICAL RESOURCES TECHNICAL REPORT, OCTOBER 2022 37 

BRIGHTLINE WEST CAJON PASS HIGH-SPEED RAIL PROJECT 

2. Introduction 

DesertXpress Enterprises, LLC (dba “Brightline West”) proposes to construct and operate the 

Cajon Pass High-Speed Rail Project (Project), a 49-mile train system capable of speeds up to 

140 miles per hour (mph) between Victor Valley and Rancho Cucamonga, California. The Project 

includes two new railway stations—one in Hesperia, and one in Rancho Cucamonga. The 

connecting station in Victor Valley would be constructed as part of a separate project that was 

evaluated in the DesertXpress Final Environmental Impact Statement (Final EIS; FRA 2011). 

The Project would be constructed within the Interstate 15 (I-15) right-of-way for 48 miles and 

on existing transportation corridors for the last mile into the proposed Rancho Cucamonga 

station. The Project would be powered by overhead electric catenary and require construction 

of one new traction power substation (TPSS) in the Hesperia area. The maintenance facility that 

was evaluated with the Brightline West Victor Valley to Las Vegas High-Speed Passenger Rail 

(HSR) Project would provide the primary maintenance functions, although layover tracks are 

anticipated at the Rancho Cucamonga station, and which could include light maintenance 

capability, such as interior cleaning and daily inspection (FRA 2020). 

Trains are expected to operate daily on 45-minute headways between Victor Valley and Rancho 

Cucamonga. The trip between Victor Valley and Rancho Cucamonga would be approximately 

35 minutes. Service would be coordinated with existing and planned Metrolink service at the 

Rancho Cucamonga station to provide a convenient connection between the HSR and 

commuter rail systems. 

The Project would be constructed and operated under a lease agreement with the California 

Department of Transportation (Caltrans) for the use of the I-15 right-of-way and the station at 

Hesperia. Brightline West would secure additional agreements with Caltrans for Right-of-Way 

Use, Design & Construction Oversight and Reimbursement, and Operations & Maintenance, as 

necessary. For the last mile of the project from I-15 to the Rancho Cucamonga Station, there 

will be Agreements with the City of Rancho Cucamonga and the San Bernardino County 

Transportation Authority (SBCTA) for land rights, construction, operations and maintenance. 

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3. Project Description 

3.1. Background 

Early Project coordination for HSR service from Victor Valley to Rancho Cucamonga began in 

2020, with Brightline West meeting with the San Bernardino County Transportation Authority 

(SBCTA) to examine a connection between Victor Valley and Rancho Cucamonga. This meeting 

resulted in a memorandum of understanding (MOU) that was fully executed in July 2020 

between Brightline West and SBCTA to study the potential of building HSR within the I-15 rightof-way between Victor Valley and Rancho Cucamonga. A separate MOU was executed in 

September 2020 between Brightline West and the Southern California Regional Rail Authority, 

which operates Metrolink, for connection to the existing Metrolink station in Rancho 

Cucamonga. Additionally, the California State Transportation Agency (CalSTA), Caltrans, the 

California High-Speed Rail Authority, and Brightline West have executed an MOU regarding the 

Project. The MOU reflects both the regional and statewide interest and value in the Project, 

including interconnectivity opportunities, and outlines how the parties will work together to 

advance their shared interest in the success of the Project. 

3.2. Project Area 

The Project would construct and operate the Cajon Pass High-Speed Rail Project, a 49-mile train 

system capable of speeds up to 140 mph between Victor Valley and Rancho Cucamonga, 

California. The Project includes two new railway stations—one in Hesperia, and one in Rancho 

Cucamonga, and will connect to another Brightline West station in Victor Valley. The station in 

Victor Valley would be constructed as part of a separate project (FRA 2020). The proposed rail 

alignment would be located within the median of the I-15 freeway between Victor Valley and 

Rancho Cucamonga except for the last mile approaching the proposed Rancho Cucamonga 

station. The Project area is depicted in 

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BRIGHTLINE WEST CAJON PASS HIGH-SPEED RAIL PROJECT 

3. 

3.3. Purpose of and Need for the Project 

3.3.1. Purpose 

The purpose of the Project is to provide reliable and safe passenger rail transportation between 

the Los Angeles metropolitan region and the High Desert of San Bernardino County. The Project 

would provide a convenient, efficient, and environmentally sustainable alternative to 

automobile travel on the highly congested I-15 highway. The Project would add capacity to the 

overall transportation system by introducing a new HSR service from Victor Valley to Rancho 

Cucamonga. The Project would reduce travel time, improve reliability, and increase the mobility 

options for travel between metropolitan regions. Travel time from Victor Valley to Rancho 

Cucamonga for Project users would be approximately 30 percent faster during normal 

conditions and at least twice as fast during congestion peak periods. The Project would reduce 

automobile vehicle miles traveled (VMT), resulting in a corresponding reduction in greenhouse 

gas emissions (GHG) and air quality emissions. 

3.3.1.1. Multi-Modal Use of the I-15 Corridor 

Operation of the Project would increase the capacity of I-15 as a multi-modal transportation 

corridor in Southern California. This increase in capacity would benefit highway operations by 

providing an alternative to automobile travel that would reduce travel time. This shift of people 

from automobile to train travel along the I-15 corridor would reduce the need for programmed 

and/or planned freeway improvement and widening projects. 

3.3.2. Need 

The Project is needed to address transportation capacity deficiencies, major points of 

congestion, limited travel mode choices, safety deficiencies, and reduce GHG emissions. 

Travel demand analysis completed on behalf of the Project in 2020 forecasts 49.1 million oneway trips between Southern California and Las Vegas in 2025, with approximately 85 percent of 

travelers making the trip by automobile. Most of these trips use the Cajon Pass segment of the 

I-15, which is capacity constrained. Further, the highway system leading into the I-15 from 

points west, east, and south, including I-10, State Route (SR) 210, I-215 and SR 60 have similar 

delays and capacity constraints. The Project would address this demand by providing a 

transportation alternative to vehicle travel, and it would allow access to the Brightline West 

service from the Greater Los Angeles and the Riverside-San Bernardino-Ontario Metropolitan 

areas, as well as points beyond, with a connection to the Metrolink system in Rancho 

Cucamonga. 

The Project would also support federal and state policies focused on climate change and the 

need to reduce VMT and associated GHG emissions. 

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3. Project Area and Vicinity 

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3.3.2.1. Capacity Constraints 

I-15 through the Cajon Pass is one of the most congested segments of I-15, with no alternative 

routes that provide comparable direct road travel capability because of the mountainous 

topography. Through the Cajon Pass, I-15 supports daily workforce commuters, recreational 

travel, and regional and interstate freight and goods movement. According to the traffic study 

prepared for the I-15 Corridor Project Initial Study/Environmental Assessment (Caltrans and 

SBCTA 2018), unreliability in travel time along segments of I-15 and surrounding roadways is 

caused by roadway capacity constraints, frequent accidents, and various factors that cause 

unanticipated congestion. Travelers using the Project would no longer need to drive through 

the most congested parts of the corridor in the Cajon Pass for interstate or commuter trips, 

thereby avoiding idling and inefficient stop-and-go traffic conditions. 

By 2045, travel speeds are expected to decrease on all but one segment of I-15 between the 

San Bernardino Valley and Apple Valley in the AM peak period, and travel speeds on most 

segments would also decrease—some by more than 10 mph—in the PM peak period (SCAG 

2020). Based on the Project Report for the I-15 Corridor Study (addition of express lanes), traffic 

volumes on I-15 between I-10 and SR 210 are expected to increase in the range of 31 to 

38 percent from 2014 to 2045. The Project Report states the existing level of service (LOS) is 

acceptable in most locations but that there are bottlenecks in each direction of travel that 

degrade traffic operation, especially between Baseline Road and SR 210. Because the express 

lane project is increasing capacity by adding express lanes, the traffic volumes are projected to 

increase by an additional 27 percent. The Project Report further mentions that, although the 

express lane project would improve conditions in the general purpose lanes in many segments, 

it would cause the segment between the I-10 and Fourth Street to worsen in the PM peak hour 

(both directions). In the AM peak hour, the segment between Arrow Route and Fourth Street 

would worsen in the southbound direction. The segment between Baseline Road and SR 210 

would continue to operate at over capacity conditions in all scenarios. 

SCAG’s Connect SoCal Goods Movement Technical Report identifies I-15 as part of the 

U.S. Department of Transportation’s (USDOT) Primary Highway Freight Network and among the 

network segments that carry the highest volumes of truck traffic in the region. It also identifies 

the entirety of the Cajon Pass as a truck bottleneck, with over 15,000 annual vehicle hours of 

delay. 

As documented above, given the attractiveness of the origins and destinations, the 

transportation capacity constraints on I-15 as described in current and predicted average daily 

traffic and LOS limit reasonable highway access between Rancho Cucamonga, Hesperia, and 

Victor Valley. 

3.3.2.2. Travel Demand 

The anticipated substantial increases in population, housing, and employment in San 

Bernardino County will result in greater demand for transportation facilities and services, 

including increased travel demand that will result in congestion on roadways if capacity does 

not keep up with the demand. The proposed Hesperia Station would provide convenient 

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connections between High Desert communities and the more urbanized San Bernardino Valley 

and Metropolitan Los Angeles. The High Desert provides lower cost housing options for 

Southern California residents, while the Rancho Cucamonga/Ontario area around Ontario 

International Airport has become a significant employment center. 

SCAG forecasts, in its 2020-2045 Regional Transportation Plan/Sustainable Communities 

Strategy (RTP/SCS), that the population of San Bernardino County will grow to 2,815,000 by 

2045, a 29 percent increase from the US Census Bureau’s 2018 population estimate of 

2,180,085, and that the number of households will grow to 875,000, a 39 percent increase over 

the 2018 household estimate of 630,633 (US Census Bureau 2020). Additionally, the 2020-2045 

RTP/SCS forecasts employment in San Bernardino County will increase to 1,064,000 by 2045, a 

72 percent increase from the US Census Bureau’s estimate of 617,828 in 2018.

While the proposed Victor Valley station site would be located at the convergence of all the 

highways en route to Las Vegas for Southern California travelers, the Rancho Cucamonga 

station would be closer to major population centers in Southern California. Compared to the 

Victor Valley station, the proposed HSR station in Rancho Cucamonga, located about 45 miles 

east of Downtown Los Angeles, would provide more direct access to the densely populated 

centers in Southern California for both drivers and Metrolink riders; 87 percent of the potential 

market for trips between Las Vegas and Southern California (equivalent to 42.7 million of the 

one-way, in-scope trips in 2025) live within 75 miles of the location of the proposed Rancho 

Cucamonga station. 

The proposed station in Rancho Cucamonga, with a Metrolink connection to Los Angeles, would 

further meet the forecasted demand of the 49.1 million one-way trips between Las Vegas and 

Southern California estimated in 2025. Similarly, the proposed Hesperia station would be at the 

convergence of US Highway 395 (US-395) and I-15, so it would serve commuters to Greater Los 

Angeles from the major corridors in the Victor Valley. 

The Project would also support SCAG’s Connect SoCal Passenger Rail Technical Report, which 

identifies closing connectivity gaps as a major strategy to increase mobility and improve 

sustainability. The Project would facilitate transit connections and would allow residents of the 

Greater Los Angeles and the Riverside-San Bernardino-Ontario Metropolitan areas to travel 

exclusively by mass transit and passenger rail to and from the High Desert of San Bernardino 

and connect to the BLW station at Victor Valley for a connection to Las Vegas. Southern 

California residents could take the Los Angeles Metro rail, regional bus systems, Amtrak, or 

Metrolink to Los Angeles Union Station to connect via the Metrolink San Bernardino Line to the 

Rancho Cucamonga station. Residents could also take the planned West Valley Connector Bus 

Rapid Transit service that will operate between the Pomona station on the Metrolink Riverside 

Line in eastern Los Angeles County and the Rancho Cucamonga station. While still in early 

planning and design stages, the planned Tunnel to Ontario International Airport (ONT) project 

may provide an additional connection from the Rancho Cucamonga station to the Ontario 

International Airport. 

Additionally, SBCTA and SCAG’s 2015 Advanced Regional Rail Integrated Vision – East (ARRIVE 

Corridor) plan proposes strategies for transitioning the Metrolink San Bernardino Line, which 

would serve the Rancho Cucamonga station, from a traditional commuter rail line to one that 

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promotes transit-oriented development. Improvements to Metrolink, its transit connections, 

and additional development of the station areas with transit-supportive uses at greater 

densities and intensities will encourage the formation of areas that are walkable and that 

provide mobility options in the region. The Project would further the goals of the ARRIVE 

Corridor plan by increasing the activity centers that can be accessed by Southern California’s 

rail network. Additionally, the Southern California Optimized Rail Expansion (SCORE) program is 

intended to increase speeds, reliability, and capacity on Metrolink lines including on the San 

Gabriel Subdivision which serves the Rancho Cucamonga station. 

In 2010, the San Bernardino Associated Governments (the predecessor agency to SBCTA) 

completed the Victor Valley Long Distance Commuter Needs Assessment, which identified a 

phased set of commuter improvement projects. Those projects ranged from expanded park and 

ride facilities to an express bus service linking the Victor Valley area of the High Desert to the 

Rancho Cucamonga Metrolink station. In 2017, SCAG and SBCTA amended the Transportation 

Improvement Program to include an expansion of the Hesperia Park & Ride area at Joshua 

Street from 188 spaces to nearly 400 spaces. The Joshua Street Park & Ride is near the Project’s 

proposed station in Hesperia. Such commuter-focused planned improvements highlight the 

need for travel options that reduce the number of single occupancy automobiles on I-15 in San 

Bernardino County, particularly through the Cajon Pass. 

SCAG’s Connect SoCal Goods Movement Technical Report identifies I-15 as part of the 

US Department of Transportation’s (USDOT) Primary Highway Freight Network and among the 

network segments that carry the highest volumes of truck traffic in the region. It also identifies 

the entirety of the Cajon Pass as a truck bottleneck, with over 15,000 annual vehicle hours of 

delay. The Federal Highway Administration has previously invested $200 million in 

improvements to the I15/I-215 interchange at the southern end of the Cajon Pass because of 

the corridor’s significance as a major truck and trade route.

FHWA’s Southern California Regional Freight Study (USDOT 2020) identifies I-15 as a major 

interstate highway corridor that provides access to the interior of the United States for goods 

arriving at the ports of the Los Angeles region and ranks it among the highest truck volume 

corridors in the western United States. The 2015 Interregional Transportation Strategic Plan 

(Caltrans 2015) identifies I-15 as a high priority corridor, among six nationally identified 

“Corridors of the Future,” and a “vital link between Mexico, Southern California, and locations 

to the north and east of the region.” I-15 also connects Southern California and the 

southwestern United States to the San Joaquin Valley’s agricultural goods via SR 58. By 

providing passenger rail capacity in the corridor, the Project would help maintain freeway 

capacity for truck freight use by removing passenger vehicles from the roadway network. 

3.3.2.3. Safety 

Alternatives to automobile travel would provide improved safety conditions on the I-15 corridor 

with diversion of vehicle trips to HSR. On a national level, comparing miles traveled via 

commercial aircraft, train, and automobiles on highways, auto travel on highways has by far the 

highest rate of passenger fatalities per mile traveled. In 2019, the average rate of passenger 

fatalities from highway travel was more than 75 times the comparable rate for travel by air and 

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34 times the comparable rate by rail. For 2016, the Bureau of Transportation Statistics’ National 

Transportation Statistics (USDOT 2018) reported a rate of passenger fatalities per 100 million 

passenger miles traveled by highway nearly 10 times greater than the rates for travel by air or 

rail. HSR is one of the safest forms of travel. 

The California Office of Traffic Safety ranks San Bernardino County 16th-worst out of 

58 counties for total fatal and injury crashes in 2018 (the most recent year of data available). 

According to the University of California, Berkeley, and SafeTREC’s Transportation Injury

Mapping System, there were 819 collisions with one or more deaths or injuries along I-15 in San 

Bernardino County in 2019. Of these, nearly one quarter (199) occurred in the 12 miles of the 

Cajon Pass, although the Cajon Pass accounts for only 6.5 percent of the length of I-15 in the 

county. 

A study by the I-15 Mobility Alliance found that the segment of I-15 from I-215 in San 

Bernardino to I-40 in Barstow had a fatality rate 0.009 per million VMT, well above the 

alliance’s performance goal of 0.003 fatalities per million. By connecting the Victor Valley to 

Rancho Cucamonga, the Project would allow more travelers to stay off segments of I-15. 

3.4. Alternatives 

3.5. Build Alternative 

The Build Alternative (i.e., the Project) consists of a proposed HSR passenger railway with 

associated infrastructure, including two proposed passenger stations. Nearly all of the Project 

would be built within the I-15 right-of-way. Near the proposed southern terminus station in 

Rancho Cucamonga, approximately 1 mile of the rail alignment would be in city street, railroad, 

or utility rights-of-way. 

The proposed rail alignment would be located within of the I-15 highway between Victor Valley 

and Rancho Cucamonga except at the approach to the proposed Rancho Cucamonga station. 

The rail alignment would be predominately at grade (the same elevation as the existing 

highway), with select segments of the alignment on aerial structures or in a trench to allow for 

grade separations and to provide a safe incline for train operation. The rail alignment would be 

predominantly single-track, with limited double-track segments in Victor Valley (2.6 miles, 

including 0.9 mile constructed as part of the DesertXpress High-Speed Passenger Train Project), 

Hesperia (5.5 miles), and Rancho Cucamonga (2 miles). This would allow for 45-minute 

headways in the opening year between Victor Valley and Rancho Cucamonga and with 

additional infrastructure, 22.5-minute headways after year 11. These headways, along with the 

ability to couple trains (double passenger capacity), would address projected ridership needs 

for the foreseeable future. 

For analytical purposes, the Build Alternative is described in three sections. Sections were 

developed to reflect developed areas with similar environmental sensitivity. The sections 

include: 

• Section 1: High Desert – from the Victor Valley station, continuing south along I-15, to the 

I-15/Oak Hill Road interchange in Hesperia 

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• Section 2: Cajon Pass – from the I-15/Oak Hill Road interchange, continuing south along 

I-15, through the Cajon Pass, to the I-15/Kenwood Avenue interchange 

• Section 3: Greater Los Angeles – from the I-15/Kenwood Avenue interchange in San 

Bernardino, continuing south along I-15, through the existing Metrolink station in Rancho 

Cucamonga to Haven Avenue 

3.5.1. Section 1 – High Desert 

The proposed rail alignment would connect to the DesertXpress High Speed Train alignment 

approximately one mile south of the Victor Valley station in Apple Valley. The Victor Valley 

station was proposed by the DesertXpress High Speed Train Project (DesertXpress Project) and 

approved in 2011 and modified by the re-evaluation in 2020. From this point, the alignment 

would continue south within the I-15 median. The rail alignment throughout Section 1 would be 

predominantly single track; however, the rail alignment would be double-track north of 

Stoddard Wells Road to the northern terminus of the alignment as it approaches the train 

platforms of the Victor Valley station. The Project would include a new structure over the 

existing CEMEX railroad bridge. Based on future discussion with CEMEX, the existing railroad 

bridge may be reconstructed as part of the DesertXpress project, in which case the alignment 

would run at-grade in the median under the railroad bridge. 

Brightline West will build a new Southbound on ramp and bridge at South Stoddard Wells Rd. to 

replace similar existing facilities further south.1 This, in turn, requires modifications of I-15 up to 

and including the Mojave River crossing. 

At the Mojave River, a new rail bridge will be constructed within the median of I-15. The 

existing I-15 bridge would be widened to accommodate the rail line. The alignment would then 

continue at grade in the I-15 median with minor roadway widenings for the remainder of 

Section 1. This portion of the alignment would interface with the following interchanges: 

Stoddard Wells Road North, Stoddard Wells Road South, D Street/E Street, Mojave Drive, Roy 

Rogers Drive/Hook Road, Palmdale Road, La Mesa Road/Nisqualli Road, Bear Valley Road, Main 

Street/Phelan Road, Joshua Street, US-395, Ranchero Road, and Oak Hill Road. 

A new substation would be constructed to support the Project along I-15, between Mesa Street 

and Mojave Street. The area is currently largely undeveloped, other than existing overhead 

power lines and utility access. 

Hesperia Station 

Section 1 includes a new passenger station in Hesperia, at the I-15/Joshua Street interchange. 

This station would serve daily travelers between the High Desert of San Bernardino County and 

the Los Angeles Basin. This would be a limited service for select southbound AM and 

northbound PM weekday on selected Brightline train coaches. The northbound on-ramp to 

Joshua Street would be realigned closer to the highway, and station parking would be on the 

north side of Joshua Street. Parking would be accessed at the location of the existing 

northbound ramp intersection. To accommodate the rail alignment, the existing US 395 

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northbound connector and the existing Joshua Street bridge would be replaced. The Joshua 

Street bridge would be reconstructed at a higher elevation, requiring raising of the I-15 ramps 

and Mariposa Road. The passenger platform would be located within the I-15 median, with 

direct access from the reconstructed Joshua Street bridge at the southern end of the doubletrack segment in Hesperia. The Project design includes adequate parking areas to 

accommodate parking demand. 

Design Elements 

Section 1 of the Project includes the following design elements. 

• Reconstructions/Interchange Modifications: Widening portions of the I-15 highway and 

modifications to interchanges at Stoddard Wells Road southbound on- and off-ramp, 

D Street/E Street, Mojave Drive, Roy Rogers Drive/Hook Road, Palmdale Road, La Mesa 

Road/Nisqualli Road, Bear Valley Road, Main Street/Phelan Road, US-395, Ranchero Road, 

Oak Hill Road, and Joshua Street 

• New Substation: Construction of a new substation along I-15 between Mesa Street and 

Mojave Street 

• Station Area: Hesperia station platform, pedestrian bridge, station access/infrastructure, 

surface parking lot accommodating approximately 360 vehicles, bus pick up/drop off areas, 

Kiss and Ride 

3.5.2. Section 2 – Cajon Pass 

Beginning at the I-15/Oak Hill Road interchange and traveling south, the alignment would run 

on the west side of the I-15 northbound lanes at grade and within the existing I-15 right-of-way. 

In this area, the I-15 runs through the San Bernardino National Forest for approximately 

12 miles. The rail alignment throughout Section 2 would be entirely single-track. 

The Project would require replacement of California Highway Patrol (CHP) emergency 

crossovers where the new guideway would block existing crossovers. Four new crossovers 

would be placed to take advantage of existing CHP access between the separated I-15 

alignments in the following locations: 

• West of Forestry Road crossing the northbound lanes 

• Approximately 1.25 miles in the southbound direction along I-15 from the crossover near 

Forestry Road, across the northbound lanes 

• West of the Baldy Mesa (Trestles) OHV Staging Area, across the northbound lanes 

• West of Perdew Canyon and approximately 1.25 miles north of Mathews Ranch Road, 

across both the north and southbound lanes 

Where I-15 northbound and southbound lanes reconnect at the foot of the Cajon Pass, the rail 

alignment would be within the I-15 median. This would require widening portions of the I-15 

highway and minor realignment of ramps at the I-15/SR 138 interchange. 

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Design Elements 

Section 2 of the Project includes the following design elements. 

• Bridges/Viaducts: None 

• Reconstructions/Interchange Modifications: Widening portions of the I-15 highway, 

including several miles of retained fill, and realignment of ramps at the I-15/SR 138 

interchange 

• Other Facilities: CHP emergency crossovers 

3.5.3. Section 3 – Greater Los Angeles 

Beginning at the Kenwood Avenue interchange, the proposed rail alignment would continue at 

grade in the I-15 median. At the I-15/I-215 interchange, the alignment would continue between 

the divided I-15 freeway at the same elevation as the highway, including the Devore 

interchange viaduct, curving to the southwest parallel to highway. The rail alignment would 

require I-15 highway and interchange ramp modifications at SR 210, Beech Avenue, Duncan 

Canyon Road, and Glen Helen Parkway. 

The rail alignment would transition to an aerial alignment and elevate over the I-15 southbound 

lanes south of Church Street and cross at Foothill Boulevard. It would continue along the west 

side of I-15 on an elevated alignment to enter the San Gabriel Subdivision and Eighth Street 

corridor. The alignment would transition onto an aerial structure and would turn west, running 

parallel to and partially within the existing rail corridor and partially within the Eighth Street 

right-of-way before entering the existing Rancho Cucamonga Metrolink station area on an 

elevated structure. The rail alignment would maintain a single-track configuration prior to 

exiting the highway median south of Church Street, where it would transition to a double-track 

configuration for the remaining distance to the Rancho Cucamonga station. At the Rancho 

Cucamonga station, an elevated station with a center platform and tracks on either side would 

be constructed parallel to and above the existing eastbound Metrolink platform, extending over 

Milliken Avenue. A new parking structure is proposed at Rancho Cucamonga station; it would 

replace existing surface parking to accommodate increased parking demand. The project design 

includes adequate parking areas to accommodate parking demand in the opening year. 

Design Elements 

Section 3 of the Project includes the following design elements. 

• Bridges/Viaducts: Viaduct of approximately 3.5 miles to cross I-15 southbound lanes and 

along existing rail corridor near Rancho Cucamonga station 

• Reconstructions/Interchange Modifications: I-15 highway and interchange ramp 

modifications at SR 210, Beach Avenue, Duncan Canyon Road, and Glen Helen Parkway 

• Station: Dedicated Brightline station adjacent to the existing Rancho Cucamonga Metrolink 

station, with vertical circulation down to the platform, shared access with existing Metrolink 

station, a share parking structure for vehicles, and a bus plaza 

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3.5.4. Construction 

The area of construction throughout the alignment would be long and narrow, hewing closely 

to the alignment centerline. Localized exceptions would occur for construction of the paralleling 

substation at the SCE Boulder Dam–San Bernardino transmission lines and for the proposed 

Hesperia station. 

“Temporary works” for construction would include laydown/staging areas, i.e., illuminated, 

enclosed, secured, stabilized, graded yards that would serve as a base for construction 

operations for a particular part of the Project. The footprints of staging areas would vary 

according to the space available, but they would provide sufficient space for unloading, storage, 

sorting, and distribution of concrete and other building materials, equipment, and large 

components required for a particular construction segment or structure. Each staging area 

would typically include a superintendent’s office, portable toilets, employee vehicle surface 

parking, space for truck loading and unloading, and heavy equipment storage. At construction 

areas for bridges, the staging areas would have storage space for steel and timber falsework 

used in supporting overhead concrete construction. 

3.6. No Build Alternative 

The No Build Alternative would not develop a passenger HSR system along I-15 between Victor 

Valley and Rancho Cucamonga. The existing I-15 corridor would remain operational, and the 

major points of congestion and transportation capacity deficiencies along the highway would 

remain. 

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4. Federal Regulations 

The following federal regulations provide protection of biological resources, including sensitive, 

threatened, and endangered species and designated critical habitats: 

• Federal Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531–1543), as amended 

• Migratory Bird Treaty Act of 1918 (MBTA; 16 U.S.C. Part 703 -712), as amended 

• Bald and Golden Eagle Protection Act (BGEPA; 16 U.S.C. § 668-668c) 

In addition, Executive Orders 13112 and 13751, National Invasive Species, provide regulatory 

directives. 

4.1.1. Federal Endangered Species Act 

The US Fish and Wildlife Service (USFWS has jurisdiction over ESA-listed plants, animals, and 

fish and their critical habitats. For the Project, FRA is the lead federal agency responsible for 

consultation with USFWS to ensure that the Project will not jeopardize the continued existence 

of an endangered or threatened species or destroy or adversely modify critical habitat. 

Critical habitat is defined in the ESA, Section 3(5)(A), as 

Specific areas within the geographic area occupied by the species on which are 

found those physical or biological features essential to the conservation of the 

species and which may require specific management considerations or 

protection. 

Critical habitat is further defined by the ESA as 

Specific areas outside the geographical area occupied by the species at the time 

it is listed but a determination has been made that such areas are essential for 

the conservation of the species. 

Implementation of ESA Section 7 (a)(2), which requires FRA to consult with USFWS, includes 

analyses of impacts on designated critical habitat, analyses of impacts on listed species, and 

analyses of indirect and cumulative impacts on listed species. 

“Incidental take” is defined as take of listed species that results from, but is not the purpose of, 

carrying out an otherwise lawful activity conducted by a Federal agency or applicant (50 CFR 

Section 402.02). “Take” is defined as, to harass, harm, pursue, hunt, shoot, wound, kill, trap, 

capture, or collect or attempt to engage in any such conduct (ESA Section 3 (19)), while “harm” 

is further defined by USFWS to include significant habitat modification or degradation that 

results in death or injury to listed species by significantly impairing behavioral patterns such as 

breeding, feeding, or sheltering. “Harass” is defined by USFWS as actions that create the 

likelihood of injury to listed species to such an extent as to significantly disrupt normal behavior 

patterns which include, but are not limited to, breeding, feeding, or sheltering (50 CFR § 17.3). 

HCPs generated under Section 10(a)(1)(B) of the ESA provide signatory parties with 

conservation tools, such as management of habitat, and mitigation approaches to compensate 

for species and habitat impacts. 

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4.1.2. Migratory Bird Treaty Act of 1918 

The MBTA authorizes the United States Secretary of the Interior to protect and regulate the 

taking of migratory birds. The MBTA protects migratory birds, their occupied nests, and their 

eggs and prevents the taking of birds listed as “migratory.” The MBTA defines migratory birds 

broadly and includes common songbirds, waterfowl, shorebirds, hawks, owls, eagles, ravens, 

crows, native doves and pigeons, swifts, martins, and swallows. The list was updated by the 

USFWS in 2020 (USFWS 2020). 

4.1.3. Bald and Golden Eagle Protection Act 

The Bald and Golden Eagle Protection Act (BGEPA) prohibits the taking or possession of and 

commerce in bald and golden eagles, with limited exceptions. Under the BGEPA, it is a violation 

to “...take, possess, sell, purchase, barter, offer to sell, transport, export or import, at any time 

or in any manner, any bald eagle commonly known as the American eagle, or golden eagle, 

alive or dead, or any part, nest, or egg, thereof....”

Under the BGEPA “take” is defined as to include pursue, shoot, shoot at, poison, wound, kill, 

capture, trap, collect, molest, and disturb. “Disturb” is further defined as follows:

to agitate or bother a bald or golden eagle to a degree that causes, or is likely to 

cause, based on the best scientific information available (1) injury to an eagle, 

(2) a decrease in its productivity, by substantially interfering with normal 

breeding, feeding, or sheltering behavior, or (3) nest abandonment, by 

substantially interfering with normal breeding, feeding, or sheltering behavior 

(50 CFR 22.3). 

4.1.4. Executive Orders 13112 and 13751, National Invasive Species 

Executive Orders 13112 and 13751, Invasive Species, direct all federal agencies to prevent and 

control introductions of invasive nonnative species, and to not authorize or carry out actions 

that are likely to cause or promote invasive species. Federal agencies should minimize the 

economic, ecological, and human health impacts caused by invasive species infestations. The 

Executive Orders require that the National Environmental Policy Act process include 

determinations of the likelihood of introducing or spreading invasive species as well as a 

description of measures being taken to minimize their potential harm. 

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5. Methodology 

This Biological Resources Technical Report was developed based on: 

• Literature and database reviews 

• Compilation of available information including maps 

• Analysis of potential direct and indirect effects on ESA-listed species and their habitats 

Construction noise, which may indirectly impact species and could extend beyond the direct 

impact footprint, was also evaluated. 

State-protected sensitive, threatened, or endangered species or state protected sensitive 

habitats were not evaluated for this federal interstate transportation project. No local agency 

information regarding sensitive plants or animal species was reviewed for the main topics of 

this report. No field surveys or other field studies were performed for this analysis. 

5.1. Study Area 

The study area for the quantitative analysis of effects on biological resources was defined as the 

area of potential direct impacts--including permanent impacts and temporary impacts which 

may occur during construction. Indirect potential effects were evaluated qualitatively. 

Appendix A provides maps showing the limits of disturbance that define the study area. 

5.1.1. Permanent Limit of Disturbance 

The permanent limit of disturbance (permanent LOD) includes the area where rail operations 

and routine maintenance would occur. The permanent LOD includes the area of railbed and 

catenary structures, as well as the full width of area cleared, cut, or filled. The permanent LOD 

includes areas of existing I-15 that would be modified (widened, raised, relocated) to 

accommodate median-running rail. Also included in the permanent LOD are the area of new 

passenger stations, parking areas, access ways, fence lines, traction power substations, and 

relocations of local roadways and highway ramps, and relocation of existing electrical towers. 

The permanent LOD was mapped based on the 30 percent engineering design for the Proposed 

Action. 

5.1.2. Temporary Limit of Disturbance 

The temporary limit of disturbance (temporary LOD) indicates the area likely to be disturbed 

during construction, including areas of temporary clearing and grading or fill, temporary access 

roads, material laydown, staging, and logistics areas. The temporary LOD was mapped to 

include the width of the entire Caltrans right-of-way. 

The duration of temporary construction disturbance at any one location was assumed to be one 

year from start of disturbance to restoration. 

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5.2. Existing Information 

Data related to ESA-listed species that may occur in the study area were accessed through the 

IPaC website (USFWS 2022a) as provided by USFWS. 

The California Natural Diversity Database (CNDDB 2022) was used to access mapped 

information on plant and animal species. Locations of designated critical habitat that may occur 

within the study area was sources from USFWS IPaC Website (2022). The CNDDB provides the 

most up-to-date geographic information systems (GIS) information on ESA-listed species. 

Information from other available biological studies which had occurred in the vicinity included: 

• I‐15/I‐215 Interchange Improvement project (Caltrans 2011) evaluated areas on the north 

side of I-15 in the vicinity of Cajon Wash crossing in San Bernardino County. 

• I‐15/New Fontana Maintenance Facility (Caltrans 2019) project studied an area along I-15 in 

Fontana. 

For each of these studies, descriptions of the executed surveys and resulting data were 

reviewed for relevance to the Project. 

5.3. Wildlife Habitats and Species Information 

The California Wildlife Habitat Relationship (CWHR) System (CDFW 2021a) is a plant community 

classification system that provides detailed information on wildlife habitat types and their 

spatial distribution in the project area. The core of the CWHR System is a database that relates 

species to each of the habitats that support them. The classification system provides maps and 

contains life history, geographic range, and management information for California’s 

amphibians, reptiles, birds, and mammals. 

Because of the wide geographic area of the Project, two separate source maps were utilized 

initially: 

• Mapped wildlife habitat information for Section 1, High Desert, was sourced from Mojave 

Desert Renewable Energy Conservation Plan vegetation GIS layer. The layer provides a 

fine-scale vegetation map of the western Mojave Desert that provides detailed information 

identifying high quality habitat and rare communities (Menke, et al. 2013; Conservation 

Biology Institute, 2022). The product follows the National Vegetation Classification Standard 

(USNVC 2021), and the mapped information was subsequently cross-referenced to CWHR 

System by the Mojave Desert Renewable Energy Conservation Plan. Information from the 

CWHR system was extracted and used. 

• Mapped wildlife habitat information for Section 2, Cajon Pass, and Section 3, Greater Los 

Angeles, was mapped from the South Coast polygon of a CALVEG (Classification and 

Assessment with LANDSAT of Visible Ecological Groupings) GIS product (USFS 2020). The 

CALVEG classification system was initially used for vegetation typing and the information 

subsequently cross-walked to the CWHR System by the originators. Information from the 

CWHR system was extracted and used. 

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Plant species names are generally in compliance with those used by Jepson eFlora (Jepson Flora 

Project 2022). Sensitive species information was collected from USFWS Information for 

Planning and Consultation (IPaC; USFWS 2022a). Migratory bird information was collected from 

the Avian Knowledge Network (AKN 2022), including information on known occurrence and 

phenology. Additional information was collected from available databases such as eBird (eBird 

2022) and iNaturalist (iNaturalist 2022). 

Both original vegetation data layers follow the California Department of Fish and Wildlife 

(CDFW) Vegetation Classification and Mapping Program (VegCAMP). The vegetation 

classification complied with Federal Geographic Data Committee standards and National 

Vegetation Classification Standards. The mapping and classification for both products included 

survey and classification work. 

The data were cleaned up to correct gaps and overlaps in areas where the two vegetation 

polygons met in the vicinity of Cajon Summit. The overlaps were accommodated with two 

codes (“overlaps” and “null”). Overlaps were resolved visually using aerial photography. Null 

polygons were dropped. Less than 10 acres were identified as Null for the entire study area. 

Following evaluation of the wildlife habitat map, it was determined that some areas had been 

developed since the time of the initial mapping exercise for both data sources. Many polygons 

were identified as one of the vegetated habitats but, upon comparison with recent aerial 

photography, they were determined to have been partially or entirely developed. To resolve 

this issue, a more contemporary urban raster overlay (called “2020 CDL”) was used to overlay 

the wildlife habitat map. The 2020 CDL urban information was sourced from the USDA National 

Agricultural Statistics Service (NASS) Cropland Data Layer (CDL) and is a raster, geo-referenced, 

crop-specific land cover data layer (USDA NASS 2022) that provides additional information. 

NASS produced the 2020 CDL using satellite imagery from several satellite systems and 

collected during a single growing season. Land covers were determined by applying heads-up 

digitizing techniques using a base of true-color and color infrared, 2010, 2014, or 2016, 1-meter 

National Agricultural Imagery Program imagery in conjunction with ancillary data and imagery 

sources. Map polygons were assessed for vegetation type, percent cover, exotics, development 

disturbance, and other attributes. The minimum mapping unit (MMU) was 10 acres; exceptions 

were made for wetlands and certain wash types (which were mapped to a 1- or 5-acre MMU) 

and areas characterized as land use polygons (which were mapped to a 2.5-acre MMU). 

The resulting 2020 CDL has a ground resolution of 30 meters. The 30-meter raster cells were 

used to overlay 2020 CDL’s urban classifications onto the habitat map, identifying all areas that 

mapped as Urban in 2020, even if they were mapped as other vegetated habitats in either of 

the two original sources habitat maps. Other areas where vegetation codes were updated with 

the 2020 CDL had their new Urban code, but also maintained their original vegetation code 

within the database to refer back to the previous vegetation coding and its transition to urban. 

In this way, changes from vegetated habitats to developed areas from the time of the initial 

source map creation was captured in the study area. This created a more contemporary map 

and assisted in avoiding over-estimation of habitat areas in the study area. 

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Historic information on Wildlife occurrences was obtained primarily from CNDDB (2022), and 

from the Information for Planning and Consultation website (IPaC) for avian species (USFWS 

2022a). 

Conservation areas were identified based on a review of the California Conservation Easement 

Database (CCED), San Bernardino County parcel information, other maps, and information 

provided by others. The CCED database provides information on easements held by trusts, nonprofit organizations, local jurisdictions, and state and national government agencies (CALANDS 

2022). Polygons of identified conservation areas were transferred to a single GIS layer and 

overlaid on wildlife habitat base maps for analysis. 

5.4. Habitat Impact Area Analysis 

Mapped wildlife habitats were used to identify potential suitable habitats for ESA-listed and 

candidate plant and wildlife species. For analysis of existing conditions and impact area, areas 

were calculated using California State Plane (NAD 1983 [2011] State Plane California 

V FIPS 0405, in U.S. feet) to generate data tables and associated information breakdowns. Data 

were processed and verified within the GIS software based upon the California State Plan 

coordinate system. 

Design specifications, proposed construction methods, mitigation measures, and operational 

protocols for the Project were reviewed and evaluated to estimate how construction and 

operation might qualitatively impact habitats, sensitive species, and designated critical habitats. 

Focused presence/absence surveys have not been performed to confirm species presence 

within the study area. Suitable habitat is assumed to be present, but the conditions of mapped 

wildlife habitat has not been evaluated. 

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6. Affected Environment 

The affected environment is described in three sections, corresponding with the Project 

sections described in Section 3.1. Starting from the northeast, just south of the Victor Valley 

passenger station in the town of Apple Valley and moving southwest to Rancho Cucamonga, 

the three sections are: 

• Section 1 – High Desert starts immediately south of the Victor Valley passenger station (this 

station is proposed under a separate project) and continues south and southwest along I-15 

to the I-15/Oak Hill Road interchange in Hesperia. 

• Section 2 – Cajon Pass from the I-15/Oak Hill Road interchange, then continues south and 

west along I-15, through the Cajon Pass, to the I-15/Kenwood Avenue interchange in 

Devore. 

• Section 3 – Greater Los Angeles from the I-15/Kenwood Avenue interchange and continues 

southwest along I-15 through Fontana to Rancho Cucamonga, then turns due west in an 

existing railway corridor to the existing Metrolink station in Rancho Cucamonga. 

The proposed rail alignment (north to south) begins in the arid Mojave Desert (High Desert), 

crosses a mountain range (San Gabriel Mountains), and travels into the marine-influenced, 

Mediterranean climate of the Los Angeles Basin. The route has high biotic, climatic, and 

geographic diversity. As stated, the entire proposed rail alignment is within Caltrans Right of 

way for I-15. 

The existing highway affects wildlife habitat conditions throughout. Disturbance adjacent to the 

existing highway includes tire and engine noise, trash, dust, and routine maintenance. 

Occasionally vehicles directly affect adjacent habitat areas due to accidents or other events that 

result in vehicles leaving the highway. 

The following subsections provide a short summary of the biotic characteristics of each section 

of the study area. 

6.1. Section 1 – High Desert 

Section 1 travels approximately 20 miles across the western extent of the Mojave Desert 

ecoregion. The Mojave Desert is known for its aridity and high biodiversity. Starting at elevation 

of approximately 3,200 feet (World Geodetic System 1984 [WGS84] datum), Section 1 rises to 

reach 4,040 feet in elevation at the Oak Hill Road/I-15 interchange at the southern end of 

Section 1. The landscape in Section 1 is characterized by flat to rolling landforms crossed by 

paved and unpaved roads connecting low-density urban and commercial developments within 

stretches of undeveloped desert vegetation. 

Section 1 crosses the Mojave River, which serves as a key wildlife corridor for the region and 

has designated critical habitat for southwestern willow flycatcher. Critical habitat is designed by 

USFWS under the ESA and provides essential habitat. Additional information about critical 

habitat and species is provided in Sections 6.9 and 6.10. 

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Section 1 crosses the urban areas of Victorville and Hesperia, which are densely developed. 

Only small patches of native plant communities and wildlife habitat remain. Native plant 

communities along the alignment of Section 1 (from north to south) exist at the following 

locations: 

• Locations of temporary construction areas, including the Blanchard Road vicinity in Hesperia 

• Mojave River crossing in Victorville 

• Oro Grande Wash crossing 

• Nisqualli Road interchange 

• Joshua Street crossing 

• US 395 interchange 

• Oak Hill Road interchange 

Public open space in the project vicinity includes the Mojave Narrows Regional Park. Mojave 

Narrows Regional Park lies just south of the Project on the Mojave River in Victorville. Public 

access enables frequent bird watching at this location. Due to the park’s proximity to the 

Project and ability of public access for bird and wildlife watching, information collected at the 

park would be relevant to the project area. 

Approximately 80 bird species observed have been observed in a single day, and over 

250 species recorded (eBird 2022) at the Mojave Narrows Regional Park. The Park contains 

open water and extensive riparian habitat dominated by cottonwood-willow forest. The area is 

important to migratory and resident bird species and known to host summer tanager, yellowbreasted chat, yellow warbler, blue grosbeak, Bell’s vireo, and vermilion flycatcher. ESA-listed 

least Bell’s vireo and western yellow-billed cuckoo may also use this habitat. Bald eagles were 

observed year-round, in all years, with golden eagle less frequently observed (eBird 2022). 

Managed by San Bernardino County for recreation, the park reports 1,500 species of watchable 

wildlife (San Bernardino County 2022). 

Hydrologic features crossed by the Proposed Action include river, stream, and wash systems. In 

Section 1, High Desert, these include Bell Mountain Wash, Oro Grande Wash, and the Mojave 

River and several small unnamed drainage features. The San Bernardino County Flood Control 

District (SBCFCD) maintains the Mojave River reach and the Oro Grande Wash in the project 

vicinity. The California Aqueduct is crossed by Section 1 and was mapped as Lacustrine habitat 

type. 

Designated critical habitat for southwest willow flycatcher is present at the Mojave River 

crossing. 

6.2. Section 2 – Cajon Pass 

Section 2 is approximately 12 miles long and traverses the Cajon Summit area of the San Gabriel 

Mountains. The Cajon Pass section travels across a largely natural landscape characterized by 

mountainous terrain and rock outcroppings that flank Cajon Canyon. This area provides a major 

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transportation gateway, a major utility corridor, managed recreation opportunities, and key 

wildlife habitat linkages between the San Bernardino Valley of the Los Angeles Basin and the 

High Desert Penrod et al. 2012) . No major residential, industrial, or commercial developments 

occur along Section 2. 

Section 2, Cajon Pass, would be developed within Caltrans right-of-way which is located on 

federal land and managed by the US Department of Agriculture, Forest Service (USFS), San 

Bernardino National Forest, Front County District. 

The proposed rail alignment initially travels alongside the northbound lanes of I-15 where the 

northbound and southbound interstate lanes are separated by approximately 0.5 mile. The 

proposed rail alignment ascends to approximately 4,260 feet (WGS84) at Cajon Summit. Past 

the summit, Section 2 travels in the median of I-15 and largely parallels Cajon Canyon, in an 

east-west segment initially, then turning south. From the Summit, the alignment descends 

approximately 2,000 feet. 

Major hydrologic features include Cajon Creek in Cajon Canyon. Approximately six major 

drainages tributary to Cajon Creek would be crossed by the project alignment, including 

Crowder Canyon Wash and Cleghorn Wash. 

The Grand Prix and Old Fires of 2003, along with the 2016 Blue Cut fire, burned vegetation and 

infrastructure along most of Section 2, affecting vegetation and wildlife habitats (CAL FIRE 

2021a). 

Designated critical habitat for arroyo toad is present in Cajon Canyon adjacent to the alignment. 

6.3. Section 3 – Greater Los Angeles 

Section 3 leaves the mountains and enters the San Bernardino Valley, which forms the 

northwestern most extent of the Greater Los Angeles basin . At the mouth of Cajon Canyon, the 

project alignment turns west where I-15 meets I-215. The alignment runs in the median of the 

highway crossing the broad alluvial washes of Cajon Wash and Lytle Creek, then skirts the base 

of the San Gabriel Mountain foothills in the town of Fontana, then turns south to travel into 

Rancho Cucamonga. 

Section 3 runs in the I-15 median, except near the terminus, where the alignment crosses over 

southbound I-15 and runs beside southbound lanes just prior to turning west and into a railway 

corridor, and to the new Rancho Cucamonga passenger station . 

Over 60 percent of Section 3 is within urbanized areas. However, several important locations 

with existing vegetation and possible suitable habitat are in Section 3; they include the 

following: 

• Cajon Wash crossing 

• Lytle Creek crossing 

In Section 3, major hydrologic features crossed include Lytle Creek and Cajon Creek at Cajon 

Wash. The SBCFCD has several flood-control features the Project would cross including groins 

and levees crossing Caltrans right-of-way. The Project would cross major engineered drainage 

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channels including Hawker-Crawford Channel, San Sevaine Channel, East Etiwanda Creek 

Channel and Day Creek Channel owned and maintained by SBCFCD (SBCFCD 2022). 

Designated critical habitat for San Bernardino Kangaroo Rat is present in Cajon Wash and Lytle 

Creek. 

Glen Helen Regional Park lies just south of the Project. Managed by San Bernardino County, the 

park provides a wide variety of recreational uses, including a large amphitheater and a raceway. 

The Project would not directly impact this area; however, because the park is near the project 

area, information on birds and wildlife observed at the park was relevant. Records from more 

than 50 years of bird watching at the park were compiled in a database of observations (ebird 

2022). A high diversity of habitats and bird species are present, with over 241 avian species 

observed (eBird 2022). Migratory bird species use the park and surroundings, with an especially 

large diversity in the fall and spring months (San Bernardino Valley Audubon Society 2021). Bald 

and golden eagles have been infrequently observed here recently. 

6.4. Existing Habitat Conservation Plan Areas and Conservation Lands 

Habitat Conservation Plans (HCPs) have been produced for areas covering the study area or 

adjacent to the study area. 

The West Mojave Habitat Conservation and Use Plan (West Mojave Plan; BLM 2004) was 

developed with the Bureau of Land Management as the lead agency and with Caltrans as a 

cooperating agency. The northern extent of the rail alignment in Section 1, High Desert, lies 

within the West Mojave Plan planning area. The West Mojave Plan focuses on conservation of 

desert tortoise and Mohave (sic) ground squirrel, along with sensitive plants and animals that 

occur in the associated natural communities. The West Mojave Plan amends the earlier Desert 

Conservation Area Plan and was developed following federal ESA requirements providing 

criteria for issue of ESA Section 10(a) permits for take of endangered species for a period of 

30 years from time of approval. 

The Western Riverside County Multiple Species Habitat Conservation Plan (Riverside County 

2004) covers 1.26 million acres in western Riverside County, with the nearest extent lying 

approximately 5 miles south of the Proposed Action. The HCP includes portions of the San 

Bernardino Mountains and many of the habitats and species present in the Project’s study area. 

Seven conservation areas occur within 1 mile of the study area (Table 1). Locations of 

conservation areas are shown on Figure 1. In total, conservation areas cover approximately 

1,000 acres in the vicinity of the project. None of these areas overlap with Caltrans right-ofway. Some of the conservation areas are also within designated critical habitat (see Figure 1). 

6.5. Wildlife Habitats 

The study area comprises approximately 2,900 acres along the entire length of the project 

alignment. Table 14 lists the mapped habitat types in the study area and provides areas of each 

habitat type in each project section. Wildlife habitats in the study area are mapped in 

Appendix A. Short summaries of the habitat types mapped in the study area are provided 

below. The wildlife habitat type descriptions were extracted from A Guide to the Wildlife 

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Habitats of California (CDFG 1988), with additional plant information from CalFlora (CalFlora 

2021) and Calscape (CNPS 2021). 

Table 14. Mapped Habitat Types within the Study Area, by California Wildlife Habitat Type 

CWHR Wildlife Habitat Type Habitat Codea 

Section 1 

High Desert 

(acres) 

Section 2 

Cajon Pass 

(acres) 

Section 3 

Greater Los 

Angeles 

(acres) 

Total Area 

(acres) 

Alkali Desert Scrub ASC 4.46 – – 4.46 

Annual Grassland AGS 4.99 – 13.89 18.88 

Barren BAR 0.16 0.63 3.78 4.57 

Chamise-Redshank Chaparral, 

Mixed Chaparral 

CRC, MCH – 3.19 – 3.19 

Coastal Scrub CSC – 5.87 9.45 15.31 

Desert Riparian DRI 9.14 0.85 – 9.99 

Desert Scrub DSC 114.10 90.07 – 204.17 

Desert Scrub, Desert Wash DSC – 1.38 – 1.38 

Desert Wash DSW, DSW – 0.18 43.99 44.16 

Eucalyptus EUC – – 0.04 0.04 

Joshua Tree JST 0.35 – – 0.35 

Juniper Jun 2.82 – – 2.82 

Mixed Chaparral MCH 0.56 93.92 40.11 134.59 

Riverine RIV 2.55 – 12.42 14.98 

Sagebrush SGB 22.02 – – 22.02 

Valley Foothill Riparian VRI 0.46 – 1.48 1.94 

Total 161.62 196.32 125.12 483.09 

a. CWHR Codes are shown on the Appendix A maps and provided here for reference. 

6.5.1. Alkali Desert Scrub 

Alkali Desert Scrub include habitats on dry lakebeds, dry riverbeds, and dry shorelines in desert 

settings. Approximately 5.5 acres of Alkali Desert Scrub are within the study area along 

Section 1, High Desert. The habitat features shrubs and, sometimes, succulent plants, all of 

which are tolerant of dry and salty soils. Common shrub species include allscale (Atriplex 

polycarpa), brittlebush (Encelia farinosa), and desert holly (Atriplex hymenelytra). Salt-tolerant 

forbs and grasses may also be present, especially as winter annuals. Trees are absent. 

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Characteristic animal species include the Mohave [sic] ground squirrel (Xerospermophilus 

mohavensis), zebra-tailed lizard (Callisaurus draconoides), and long-nosed leopard lizard 

(Gambelia wislizenii). 

6.5.2. Annual Grassland 

Annual grassland habitats are characterized as having dramatic vegetation coverage differences 

from season to season, with lush, early-year, green growth as a response to winter rains 

followed by dry, brown, cured vegetation during the dry season. During drought years, 

vegetation is dry or absent throughout the year. Approximately 19 acres of the study area are 

mapped as annual grassland, with about 14 acres mapped along Section 3, Greater Los Angeles. 

In most locations, this community is dominated by introduced grass species mostly of 

Mediterranean origin and includes cheatgrass (Bromus tectorum), soft brome (Bromus 

hordeaceus), slender wild oats (Avena barbara), and wild oats (Avena fatua). The non-native 

grasses are more fire-adapted than non-native species. Many animals use Annual Grassland for 

foraging, especially when the area is adjacent to other structural habitat elements such as cliffs, 

aquatic areas, shrub areas, or other nearby areas suitable for perching and cover. Mammals 

typically found in this habitat include the black-tailed jackrabbit (Lepus californicus), California 

ground squirrel (Otospermophilus beecheyi), Botta's pocket gopher (Thomomys bottae), 

western harvest mouse (Reithrodontomys megalotis), California vole (Microtus californicus), 

badger (Mustelidae mephitidae), and coyote (Canis latrans). This habitat provides foraging 

habitat for a wide variety of birds, including raptors and other migratory birds. 

6.5.3. Chamise-Redshank Chaparral, Mixed Chaparral 

Chamise-Redshank Chaparral and Mixed Chaparral is a heterogeneous mix of two habitat types 

at scales below the mapping resolutions. Chamise-Redshank Chaparral habitat is a dense 

habitat where shrubs with stiff, overlapping, interwoven branches are so dense that there is no 

herbaceous vegetation below the shrub canopy. Chamise (Adenostoma fasciculatum) and or 

redshank (Adenostoma sparsifolium) may comprise the entire community. Distinguishing 

Chamise-Redshank Chaparral from Mixed Chaparral and Coastal Scrub is determined by percent 

cover of chamise and redshank and other shrub species. Less than 4 acre is mapped along 

Section 2, Cajon Pass. 

6.5.4. Coastal Scrub and Riversidean Alluvial Fan Sage Scrub 

In southern California, the typical community components of Coastal Scrub include a large 

variety of soft stemmed shrubs, such as California sagebrush (Artemisia californica) and 

California buckwheat (Eriogonum fasciculatum). In this habitat, shrubs may drop their leaves 

during the dry months (drought deciduous), and, generally, plant density and structure allow 

enough light to support an herbaceous understory. 

“Coastal sage scrub” is an equivalent designation for Coastal Scrub habitat in Southern 

California and, further within the study area, a very specific vascular plant association, called 

“Riversidean Alluvial Fan Sage Scrub” has been recognized (White and Padley 1997).

Riversidean Alluvial Fan Sage Scrub habitat is a distinct and rare plant community found on 

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alluvial fans at the foothills of the San Gabriel Mountains. In the project area, this includes Lytle 

Creek and Cajon Wash areas. 

Riversidean Alluvial Fan Sage Scrub plant communities consist of a specific subset of plants 

within Coastal Scrub habitat types that are distinctly different mix of plants from Coastal Scrub 

habitat type elsewhere in California. 

Plant species present in the Riversidean Alluvial Fan Sage Scrub plant community include 

California sagebrush (Artemisia californica), white sage (Salvia apiana), various buckwheat 

species (Eriogonum spp.), golden yarrow (Eriophyllum confertiflorum), and coastal pricklypear 

(Opuntia littoralis). Scale-broom (also known as California broomsage; Lepidospartum 

squamatum) is an indicator species for the Riversidean Alluvial Fan Sage Scrub association. 

The habitat is known to support several ESA-listed species, including coastal California 

gnatcatcher (Polioptila californica californica), San Bernardino Merriam’s kangaroo rat 

(Dipodomys merriami parvus), slender-horned spineflower (Dodecahema leptoceras), and Santa 

Ana River woolly-star (Eriastrum densifolium ssp. sanctorum). Designated critical habitat for San 

Bernardino Merriam’s kangaroo rat is mapped on alluvial fan landforms supporting, or 

potentially supporting, Riversidean Alluvial Fan Sage Scrub. 

The plant community is found throughout the northern portions of the City of Fortuna and 

Rialto and in unincorporated San Bernardino County in the vicinity of I-15. Thus, while a 

relatively small area of approximately 15 acres is mapped along Section 3, Greater Los Angeles, 

at Cajon Creek and Lytle Creek, the vegetation and habitat elements in the study area is of high 

importance. 

6.5.5. Desert Riparian 

Desert Riparian is characterized as dense groves of low, shrubby trees that may also include 

areas of woodlands composed of small- to medium-sized trees, all of which are adjacent to 

water. Along the Mojave River, willows (Salix exigua and Salix laevigata) form the riparian 

shrub community, while Fremont cottonwood (Populus fremontii) and Arizona ash trees 

(Fraxinus velutina) create an overstory. This habitat type is rare within the region and is 

associated with several endangered species. In the study area, approximately 10 acres of Desert 

Riparian habitat are included, with most of this area located at the Mojave River crossing in 

Section 1, High Desert. 

6.5.6. Desert Scrub 

Desert Scrub habitat is characterized by widely spaced shrubs with low levels of canopy cover 

and, depending on elevation, season, and disturbance, has either diverse herbaceous growth 

between shrubs or low plant coverage with nearly bare earth between shrubs. Creosote bush 

(Larrea tridentata) is the characteristic shrub present. Approximately 204 acres in the study 

area are mapped as Desert Scrub, occurring in Sections 1 and 2. 

The primary resident wildlife species that use Desert Scrub habitat include reptiles and rodents; 

however, many species use this habitat for foraging. The protected desert tortoise (Gopherus 

agassizii) is dependent on this habitat. Other species typical of Desert Scrub habitat include 

black-throated sparrow (Amphispiza bilineata), sage sparrow (Amphispiza bellii), desert kit fox 

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(Vulpes macrostis arsipus), various pocket mice and kangaroo rats, Mohave ground squirrel, 

and a variety of lizards and snakes, such as side-blotched lizard (Uta stansburiana), basin 

whiptail (Aspidoscelis tigris tigris), and Mohave Desert sidewinder (Crotolus cerastes cerastes). 

Common raven (Corvus corax) are generalist predators and their numbers have recently 

increased in this habitat and adjacent urbanizing areas (Boarman 2003 and Boarman et al. 

2006). 

6.5.7. Desert Wash 

Desert washes flow intermittently, usually only following heavy precipitation. Desert Wash 

habitat occurs where vegetation is present in desert washes. Some desert washes are not 

naturally vegetated and, thus, would be mapped as Barren habitat. The vegetation community 

consists of plants adapted to intermittent presence of surface water. The plant community is 

often taller and denser than surrounding desert habitats, thereby providing vertical structure 

and cover. Native plant species include desert pearl (Ambrosia salsoa), threadleaf ragwort 

(Senecio flaccidus), and four-winged saltbush (Atriplex canescens). In some locations, washes 

are colonized by invasive tamarisk (Tamarix chinensis) or Russian olive shrubs (Elaeagnus 

angustifolia). 

In Desert Wash habitat, the occasional presence of surface water along with dense shrubs 

provide cover and breeding habitat for many species that forage in the adjacent desert 

habitats. Approximately 44 acres are mapped in the study area, nearly all of it along Section 3, 

Greater Los Angeles, in Cajon Wash. 

6.5.8. Eucalyptus 

Eucalyptus habitats are dominated by non-native eucalyptus plants. Depending on which 

eucalyptus species are present, this habitat includes trees or shrubs, such as red gum 

(Eucalyptus camaldulensis). This non-native habitat provides limited support for wildlife. 

Approximately 0.4 acre is mapped along Section 3 adjacent to I-15 in Rancho Cucamonga. 

6.5.9. Joshua Tree 

Joshua Tree (Yucca brevifolia) habitat supports widely scattered Joshua trees in open 

shrublands with low broad-leaved evergreen and deciduous shrubs and limited herbaceous 

understory. Other plants present with Joshua trees include California juniper (Juniperus 

californica), Mojave yucca (Yucca schidigera), big sagebrush (Artemisia tridentata tridentata), 

Nevada ephedra (Ephedra nevadaensis), California buckwheat, Cooper’s goldenbush 

(Ericameria cooperi), burrobush (Ambrosia dumosa), Anderson's thornbush (Lycium andersonii), 

Cooper’s box thorn (Lycium cooperi), spiny desert olive (Menodora spinescens), and beavertail 

cactus (Opuntia basilaris). Joshua Tree habitat is generally located on the periphery of the 

Mojave Desert. 

Because Joshua trees grow tall within an otherwise shrubby habitat, they are critical to habitat 

function, providing perches and nesting sites. Common animal species include ladder-backed 

woodpecker (Dryobates scalaris), cactus wren (Campylorhynchus brunneicapillus), Scott's oriole 

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(Icterus parisorum), and desert spiny lizard (Sceloporus magister). Approximately 0.4 acre of 

this habitat is mapped in the study area in Section 1, High Desert, in the Hesperia vicinity. 

6.5.10. Juniper 

Juniper habitats are characterized as woodlands with open to dense aggregations small trees or 

shrubs. Utah juniper (Juniperus utahensis), California juniper (Juniperus californica), and Tucker 

oak (Quercus john-tuckeri) are the most common plant species, with other associated shrubs 

and herbaceous plants. 

Dusky chipmunk (Tamias obscurus davisii) and common ravens are common in this habitat. The 

acreage covered by juniper woodlands tends to increase under fire suppression and 

subsequently decreases immediately following wildfire. Approximately 3 acres of Juniper 

habitat is mapped along Section 1, High Desert, in the Hesperia vicinity. 

6.5.11. Mixed Chapparal 

Mixed Chapparal habitat consists of woody, stiff-stemmed, thick-leaved, mainly evergreen 

shrubs. Plant diversity is generally high, with many different species of woody shrubs possibly 

present. 

This habitat is wildfire-adapted as long as wildfires return at natural frequencies, but it can be 

damaged by intense wildfire following long periods of fire suppression, or too frequent fires. 

Approximately 134 acres of Mixed Chapparal are mapped in the study area. Mixed Chapparal 

occurs along all three project sections with most area split between Section 2, Cajon Pass, and 

Section 3, Greater Los Angeles. 

Plant species include scrub oak (Quercus dumosa), coyote brush (Bacharis pilularis), and several 

species of chamise (Adenostoma spp.), ceanothus (Ceanothus spp.), and manzanita 

(Arctostapylos spp.). Commonly associated shrubs include birchleaf mountain mahogany 

(Cercocarpus betuloides), silk-tassel (Garrya flavescens), poison-oak (Toxicodendron 

diversilobum), coffeeberry (Frangula californica), hollyleaf cherry (Prunus ilicifolia), and 

California fremontia (Fremontia californica). 

No wildlife is restricted to just Mixed Chapparal, with species using Mixed Chapparal habitats 

also present in adjacent habitats. Common bird species that use shrub habitats include western 

scrub-jay (Aphelocoma californica), California towhee (Melozone crissalis), and various 

hummingbirds, and sparrows. A variety of animals including wood rats (Neotoma fuscipes 

macrotis) and brush rabbits (Sylvilagus bachmani) use this shrub habitat for cover. 

6.5.12. Riverine 

Riverine habitat is mapped as areas of streams and rivers with intermittent or continually 

running water. Approximately 15 acres of Riverine habitat have been identified in the study 

area and occur across all three project sections. Most of this habitat is located in either the 

Mojave River or Cajon Canyon. Riverine habitat is generally rare in this xeric environment. 

Open water provides habitat for a broad variety of wildlife and is essential for some species 

such as river otters (Lontra canadensis), beaver (Castor canadensis), as well as multiple species 

of shorebirds and waterfowl. 

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6.5.13. Sagebrush 

Approximately 22 acres of Sagebrush habitat occur along Section 1, High Desert. This habitat is 

typified by almost pure stands of big sagebrush (Artemisia tridentata ssp. tridentata) with a 

general low plant diversity relative to other shrub habitats. Shrub density is variable by location 

and disturbance regime and can range from sparsely distributed to closely spaced shrubs. 

Common wildlife in Sagebrush habitat includes jackrabbits (Lepus californicus), cottontail 

rabbits (Sylvilagus spp.), ground squirrels, least chipmunk (Neotamias minimus), kangaroo rats 

(Dipodomys spp.), wood rats, pocket mice (Perognathus longimembris), deer mice (Peromyscus 

maniculatus), grasshopper mice (Onychomys torridus), sagebrush vole (Lemmiscus curtatus), 

and desert bighorn sheep (Ovis canadensis nelsoni). Birds of the sagebrush habitat include 

chukar (Alectoris chukar), black-billed magpie (Pica hudsonia), gray flycatcher (Empidonax 

wrightii), pinyon jay (Gymnorhinus cyanocephalus), sage thrasher (Oreoscoptes montanus), and 

several sparrows (multiple genera), and hawks (multiple genera). 

6.5.14. Valley Foothill Riparian 

Valley Foothill Riparian is one of two forested habitats along the Project alignment and is 

generally rare within the region. The habitat is restricted to stream and river valley floodplains 

bordered by alluvial fans and slightly dissected terraces at lower foothills, generally with gently 

sloping topography. Approximately 2 acres of Valley Foothill Riparian habitat is mapped in the 

study area occurring in Sections 1 and 3 and associated with Cajon Canyon and the Mojave 

River. 

Tree species present are usually broad-leafed and winter deciduous. While relatively limited in 

area, linear riparian habitats that traverse through various landscapes serve as key wildlife 

linkages and migratory and dispersal corridors. Cottonwood (Populus spp.) and California 

sycamore (Platanus racemosa) are dominant tree species, with white alder (Alnus rhombifolia) 

and boxelder (Acer negundo) as subdominant trees. Wild grape (Vitis californica), wild rose 

(Rosa californica), and willows (Salix spp.) are often present and important to create a 

multi-layered vegetation canopy. With the presence of trees and water along with high plant 

diversity with overstory and understory layers, this habitat supports an abundance of wildlife 

for foraging and breeding. 

6.5.15. Urban and Barren Habitat Types 

Approximately 2,415 acres, across all three project sections, were mapped as Urban. The Urban 

habitat type is typically dominated by development and impervious surfaces, such as roadways, 

buildings, parking areas. Vegetation, when present, consists mainly of ornamental and nonnative species. Planted tree groves, lawns, gardens, shrub cover, and street-side plantings occur 

in this habitat and generally this habitat is actively maintained. 

Barren habitat type is defined as having less than 10 percent tree and shrub cover and less than 

2 percent vegetation cover from other plants. The habitat includes rock, gravel, and bare soil 

areas. In the study area, some areas may be classified as Barren if vegetation is widely spaced 

or absent, such as in washes. Approximately 4.57 acres are mapped as Barren in the study area. 

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In Urban areas, animal species present are those that can successfully utilize small habitat areas 

and are generally tolerant of disturbances, including human presence, noise, lighting, and other 

urban characteristics. These species include racoon (Procyon lotor), skunk (Mephitis spp.), 

squirrels (Sciurus spp.), American robin (Turdus migratorius), American crow (Corvus 

brachyrhynchos), jays (multiple genera), raven, various other small mammals, and coyotes. 

6.6. Habitat Connectivity and Wildlife Movement 

Corridors where wildlife move between larger habitat patches are generally referred to as 

habitat linkages or wildlife movement corridors. Wildlife movement corridors present include 

the Mojave River, Oro Grande Wash, Lytle Creek, and Cajon Wash. A key east-west wildlife 

corridor occurs along Cajon Canyon linking the San Bernardino Valley of the Los Angeles Basin 

and the Mojave Desert (generally north-south). The mountain area also serves as a generally 

east-west corridor crossing Cajon Canyon. 

San Bernardino County mapped major wildlife corridors and wildlife-focused policy areas, 

including the location of the north-south wildlife corridors through Cajon Canyon (Figure 2). 

Policy areas on the figure indicate locations where San Bernardino County wildlife management 

policies have been applied due to the presence of federally designated critical habitat and 

assumed presences of ESA-listed species. Wildlife corridors allow for short-term movements, 

long-term dispersal, or one time emigration. Wildlife movement corridors allow species to 

travel through a landscape, or they may serve as core habitat for some species. Wildlife 

corridors are critical to allowing safe travel for large mammals and predator species that travel 

large distances to find mates and enabling genetic diversity essential to maintaining 

widely-spread species. 

Barriers to wildlife movement occur where development has fragmented habitat or otherwise 

results in effects that cause wildlife to avoid an area. A 2012 study evaluated linkages between 

wildlife habitat locations in the Mojave Desert portion of the study area (Penrod et al. 2012) 

CDFW in conjunction with federal partners has identified barriers to priority movement along 

highway corridors. One priority barrier to wildlife crossing has been identified in the study area 

- Barrier ID W060 I-15 at Cajon Pass, where approximately 2.7 miles of highway between Cajon 

Junction and Baldy Mesa Road on I-15 lack suitable wildlife crossings for mule deer, mountain 

lion, bear, and bighorn sheep (CDFW 2020). 

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Figure 4. Wildlife Corridors in the Project Area, as Mapped by San Bernardino County. 

6.7. Migratory Birds 

Migratory birds pass through the Project region in fall and spring along the Pacific Flyway. This 

migratory corridor extends from Alaska to the southern tip of South America and includes the 

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entire width of California. Approximately 19 migratory species are likely to be present in the 

study area each year (AKN 2022). 

Birds of conservation concern warrant special attention (USFWS 2022a) and are of concern 

throughout their range. Birds of conservation concern include the following: Allen’s 

hummingbird (Selasphorus sasin), black-chinned sparrow (Spisella atrogularis), California 

thrasher (Toxostoma redivivum), Cassin’s finch (Carpodacus cassinii), Clark’s grebe 

(Aechmophorus clarkii), common yellowthroat (Geothlypis trichas sinuosa), Costa’s 

hummingbird (Calypte costae), Lawrence’s goldfinch (Carduelis lawrencei), long-eared owl (Asio 

otus), Nuttall’s woodpecker (Picoides nuttallii), oak titmouse (Baeolophus inornatus), 

olive-sided flycatcher, (Contopus cooperis), rufous-winged sparrow (Aimophilia carpalis), 

tricolored blackbird (Aeglaius tricolor), and wrentit (Chamaea fasicata). 

Habitat patches with cover and water sources are critical stopover points for migrating birds. In 

the study area, the riparian habitats of the Mojave River provide a vital link for migratory birds. 

Just upriver from the study area, the Mojave Narrows Regional Park in Victorville provides 

important habitat for resident and migratory birds. Migratory birds may also use riparian areas 

in Cajon Canyon, Cajon Wash, and Lytle Creek. 

6.8. Bald and Golden Eagles 

Bald eagle (Haliaeetus leucocephalus) and golden eagle (Aquila chrysaetos) are large raptors 

present in the region and may use the project area. Breeding adult pairs, non-breeding 

juveniles, and subadult eagles occur as residents and as transient migrants. 

Bald eagles establish a territory and nest in the vicinity of open water. Bald eagles are 

monogamous and may mate for life. In the Project area, known territories occur near the 

Mojave River and south of the project area at the Santa Ana River (CNDDB 2022). Bald eagle 

prey on a number of species, but fish and smaller waterfowl are the primary prey in most areas. 

A well-known breeding bald eagle pair use area around Big Bear Lake in the San Bernardino 

Mountains, approximately 25 miles south of the project area. 

Golden eagles are one of the largest, fastest, and nimblest raptors in North America and can 

live up to 30 years in the wild. Their range includes the entire Project area where they tend to 

be present year-round in established territories. They use open habitats, including juniper, 

grasslands, desert scrub and washes, valley and foothill riparian areas, and open areas created 

by wildfire on rolling foothills, canyons, and mountainous landscapes. 

Golden eagles are monogamous and may mate for life, building large nests which they tend to 

reuse. Nests are built on cliff-walled canyons, occasionally in large trees in open areas, and they 

are known to sometimes build nests on electrical transmission and wind turbine towers. Golden 

eagles hunt rodents, rabbits, ground squirrels, and prairie dogs, and are known to 

opportunistically consume dead livestock and other carrion. The Apple Valley area has a known 

occupied territory reported in 2011 (CNDBB 2021), but more recent data regarding occupation 

was not identified. Golden eagles have been recently observed in the Cajon Canyon area and at 

Glen Helen Regional Park (eBird 2022). 

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Threats to these large raptors include habitat loss, secondary assimilation of rodenticides and 

insecticides, recreation, road strikes, electrocution, and wind turbine strikes. 

6.9. ESA-Listed and Candidate Species in the Study Area 

Table 15 lists the ESA-listed and candidate plant and animal species that were identified in the 

study area (USFWS 2022a and 2022b). 

Table 15. ESA-Listed Species that May Occur in the Project Area 

Species Name Federal Status 

Suitable Habitat 

Likely Present 

Flowering Plants 

Braunton’s milk-vetch (Astragalus brauntonii) Endangered No 

San Diego ambrosia (Ambrosia pumila) Endangered No 

Santa Ana River woolly-star (Eriastrum densifolium ssp. sanctorum) Endangered Yes 

Slender-horned spineflower (Dodecahema leptoceras) Endangered Yes 

Amphibians 

Arroyo (southwestern) toad (Anaxyrus californicus) Endangered Yes 

Mountain yellow-legged frog (Rana muscosa) Endangered No 

Birds 

California condor (Gymnogyps californianus) Endangered No 

Coastal California gnatcatcher (Polioptila californica californica) Threatened Yes 

Least Bell’s vireo (Vireo bellii pusillus) Endangered Yes 

Southwestern willow flycatcher (Empidonax traillii extimus) Endangered Yes 

Western yellow-billed cuckoo (Coccyzus americanus occidentalis) Threatened Yes 

Fish 

Mohave tui chub (Gila bicolor ssp. mohavensis) Endangered No 

Santa Ana sucker (Catostamus santaanae) Threatened No 

Insects 

Delhi Sands flower-loving fly (Rhaphiomidas terminatus abdominalis) Endangered No 

Monarch butterfly (Danaus plexippus) Candidate for 

listing 

Yes 

Mammals 

San Bernardino Merriam’s kangaroo rat (Dipodomys merriami parvus) Endangered Yes 

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Species Name Federal Status 

Suitable Habitat 

Likely Present 

Reptiles 

Desert tortoise (Gopherus agassizii) Threatened Yes 

Sources: USFWS 2022d and 2022b 

6.9.1. ESA-Listed Plant Species 

6.9.1.1. Braunton's Milkvetch (Endangered) 

Braunton’s milkvetch (Astragalus brauntonii) is a perennial native herb that was listed as 

endangered in 1997 (USFWS 1997). The species is endemic to California, where it grows in 

coastal prairie grasslands, coastal sage scrub, and chaparral plant communities of the Los 

Angeles Basin. It appears to be restricted to calcareous soils. When it was listed in 1999, 

approximately 3,000 individual plants were known, and none was in the vicinity of the study 

area (USFWS 1999). According to Calflora, the species was documented in the San Gabriel 

Mountains in San Bernardino County in 2018, but not within 15 miles of the Project (Calflora 

2021). 

6.9.1.2. San Diego Ambrosia (Endangered) 

The San Diego ambrosia (Ambrosia pumila) was listed as endangered in 2002 due to 

degradation of habitat (USFWS 2002a). The species is a perennial herb endemic to southern 

California. It occurs in a variety of habitats, including upland clay slopes, sparse grasslands, 

marginal wetlands, and alkali playas. The species flowers from May through October. The 

species has not been observed in San Bernardino County (Calflora 2021). 

6.9.1.3. Santa Ana River Woolly-Star (Endangered) 

The Santa Ana River woolly-star (Eriastrum densifolium ssp. sanctorum) was listed as 

endangered in 1987 (USFWS 1987; CNDDB 2022). The Santa Ana River woolly-star is a perennial 

herb found in Riverside and San Bernardino Counties; it formerly extended into Orange County. 

Generally, the Santa Ana River woolly-star grows on sandy to gravelly soils at elevations ranging 

from 450 feet to 2,000 feet above mean sea level. The plant typically blooms from June through 

August. 

The Western Riverside County Multispecies HCP (USFWS 2003) and the Upper Santa Ana River 

Wash HCP (ICF 2020) address Santa Ana River woolly-star conservation. While both HCPs 

address geographic areas south of the project vicinity, the HCPs provided information on 

suitable habitat characteristics and conservation approaches. 

Suitable habitat for the woolly-star is present within Cajon Canyon and Lytle Creek (Buck-Diaz 

and Evans 2011) in the study area. No Santa Ana River woolly-star plants were found during 

surveys associated with Caltrans’ I-15/I-215 Interchange Improvement project (Caltrans 2011) 

or at the I-15/New Fontana Maintenance Facility area (Caltrans 2019). 

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6.9.1.4. Slender-Horned Spineflower (Endangered) 

The slender-horned spineflower (Dodecahema leptoceras) was listed as endangered in 1987 

(USFWS 1987; CNDDB 2022). The slender-horned spineflower is an endemic annual plant in the 

buckwheat family that occurs in foothills of the San Gabriel Ranges of Los Angeles, San 

Bernardino, and Riverside Counties from 600 to 2,225 feet in elevation (Calflora 2021). The 

plant blooms from April to June on silt soils typical of alluvial fans and on higher benches within 

the alluvial fan areas subject to only rare flood events (USFWS 2010). The plant occurs among a 

broad array of associated plants (trees, shrubs and herbs) without a single associated indicator 

species or community type (Allen 1996). 

Populations are known from the Lytle Creek, Cajon Canyon, and Cajon Wash areas in the 

project area (USFWS 2010). No slender-horned spineflower plants were found during surveys 

associated the I-15/I-215 Interchange Improvement project (Caltrans 2011) or the I-15 New 

Fontana Maintenance Facility (Caltrans 2019). 

6.9.2. ESA-Listed Animal Species 

6.9.2.1. Arroyo (Southwestern) Toad (Endangered) 

The arroyo (southwestern) toad was listed as an endangered species in 1994 (USFWS 1994b). 

The arroyo toad is a small toad restricted to rivers and streams that have persistent water along 

with shallow, gravelly pools adjacent to sandy terraces. Breeding occurs from late March until 

mid-June. 

Arroyo toads were historically found along many drainages in southern California from San Luis 

Obispo County to San Diego County, but now they survive as small, isolated populations within 

the headwaters of a few of those drainages (USFWS 2011). In the project vicinity, one 

population of arroyo toad had been identified as recently as 2007 along the in the Cajon Wash 

on the west side of I-15 on the San Bernardino National Forest (CNDDB 2022). A second 

population had been identified at the Mojave River at Victorville which may have been 

extirpated with no detections in more than 30 years (USFWS 2014). 

6.9.2.2. Mountain Yellow-Legged Frog (Endangered) 

The mountain yellow-legged frog was listed as endangered in 2002 (USFWS 2002b). The species 

is highly aquatic and is rarely found away from water. The frog hibernates and emerges shortly 

after the snow melts to forage and breed. The current range of the species includes the Angeles 

National Forest northwest of the I-15 corridor (USFWS 2022a). The frog is highly unlikely to be 

in the project vicinity because there is no perennial water. 

6.9.2.3. California Condor (Endangered) 

The California condor was listed as endangered in 1967 (USFWS 1967) due to loss of habitat, 

impairment of reproduction from pesticide use, and direct mortality from shooting and egg 

collecting. The condor’s current mapped range includes northern Rancho Cucamonga and Cajon 

Canyon where I-15 traverses along the eastern canyon edge and crosses over Cajon Wash 

(USFWS 2022a). A condor’s full range can be a 30-kilometer radius from its nesting site. 

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The California condor feeds on the carcasses of a variety of animals, including domestic cattle, 

sheep, horses, and squirrels. Condors require open terrain to forage because they need a long 

runway for approach and takeoff. While they formerly foraged along coastal shorelines and 

rivers, current foraging areas are almost entirely privately-owned ranch lands (Tesky 1994). 

The condor is protected under several HCPs covering geographic areas from Bakersfield, 

California, approximately 150 miles northwest of Rancho Cucamonga and the Project. 

Condors could be present in the study area and nesting throughout the year. However, given 

condors’ proclivity for steep cliffs and open ranch land, there is a low likelihood that they would 

be nesting or foraging within or near the I-15 corridor. 

6.9.2.4. Coastal California Gnatcatcher (Threatened) 

The USFWS listed the coastal California gnatcatcher as a threatened species in 1993 due to loss 

of habitat (USFWS 1993a). The coastal California gnatcatcher is a small, drab, insectivorous 

songbird endemic to the mountains of southern California. The bird is typically found in stands 

of coastal scrub, where it breeds between mid-February and the end of August with peak 

activity from mid-March to mid-May (USFWS 2019). During the non-breeding season, it may 

forage in chaparral habitats (USFWS 2007). The bird’s diet consists of leafhoppers, beetles, 

bugs, and spiders. 

Suitable habitat for the gnatcatcher is present within the Riversidean Alluvial Fan Sage Scrub 

habitats that occur within Cajon Canyon and Lytle Creek (Buck-Diaz and Evans 2011). The 

species is known to utilize adjacent habitat types that occur in the vicinity of Coastal Scrub for 

foraging and other activities. The species has been documented adjacent to I-15 around Lytle 

Creek and in northeastern Rancho Cucamonga (CNDDB 2022). 

6.9.2.5. Least Bell’s Vireo (Endangered) 

The least Bell’s vireo (Vireo bellii pusillus) was listed as an endangered species in May 1986 

(USFWS 1986). 

The bird prefers primarily riparian habitat with dense vegetation cover within 6 feet of the 

ground and a dense, stratified canopy. Least Bell’s vireo typically breeds from late March 

through mid-September. 

Past observations of paired least Bell’s vireos and nests suggest nesting activity has occurred in 

the project vicinity along the Mojave River, from the Mojave Narrows Regional Park to Bell 

Mountain Wash near Victorville (USFWS 1994a). Recent sightings of the birds have occurred 

along the Mojave River, just north of the I-15 crossing (CNDDB 2022). 

6.9.2.6. Southwestern Willow Flycatcher (Endangered) 

The southwestern willow flycatcher was added to the federal endangered species list in March 

1995 (USFWS 1995). The southwestern willow flycatcher breeds in dense riparian shrub 

communities where surface water is present, including at rivers, wetlands, and reservoirs. 

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Suitable habitat for the southwestern willow flycatcher may be present, and the species has 

been spotted multiple times throughout Cajon Canyon (CNDDB 2022). Riparian habitat in the 

Mojave River provides suitable habitat. 

The Town of Apple Valley Multispecies HCP and the Desert Renewable Energy Conservation 

Plan both address conservation approaches for this species in the vicinity of the project area 

(Apple Valley 2022). 

6.9.2.7. Western Yellow-Billed Cuckoo (Threatened) 

The Western Distinct Population Segment (DPS) of yellow-billed cuckoo was listed as a 

threatened species in 2014 (USFWS 2014b). The Western DPS is a distinct population that 

occurs west of the Rocky Mountains. The western yellow-billed cuckoo is currently found only 

in the southern part of its breeding range in California, Nevada, Arizona, New Mexico, and parts 

of Mexico (USFWS 2021). 

The majority of the Mojave River is characterized by sub-surface flow, but in the vicinity of the 

study area, a 15-mile river reach is present where shallow subsurface and some surface flow 

support riparian cottonwood-willow forest that provides suitable habitat features for the 

western yellow-billed cuckoo. The species was documented as present in early July 2017 and 

was reported to have been observed in 2020 at the Palisades Ranch conservation property 

approximately 11 miles downstream of the Proposed Action on the Mojave River (Estacio 

2020). 

6.9.2.8. Mohave Tui Chub (Endangered) 

The Mohave Tui chub (Gila bicolor ssp. mohavensis) is the only fish native to the Mojave River 

and was listed as endangered in 1970 (USFWS 1970). Damming of the river’s headwaters and 

the introduction of non-native arroyo chub led to its decline (CDFW 2021b). The lack of surface 

water and degradation of riverine habitats have removed the fish from many locations. 

Formerly, the fish utilized deep pools and slough areas throughout the Mojave River. Currently, 

the fish is known to occur only in three locations, none of which occur within 60 to 90 miles of 

the study area (CDFW 2021b). 

6.9.2.9. Santa Ana Sucker (Endangered) 

The Santa Ana sucker was listed as threatened in 2000 (USFWS 2000). Its current range includes 

the Santa Ana River approximately 15 miles southeast of Rancho Cucamonga and outside of the 

project area (USFWS 2013b). 

6.9.2.10. Delhi Sands Flower-Loving Fly (Endangered) 

The Delhi Sands flower-loving fly (Rhaphiomidas terminatus abdominalis) was listed as 

endangered in 1993 and is the first and only fly to be listed under the ESA (USFWS 1993b). The 

fly uses the Delhi Sands, a fine sandy soil. The soil formed on sandy floodplains, alluvial fans, 

and terraces in San Bernardino and Riverside Counties (USDA NRCS 2022). The fly’s current 

range includes the southern part of Rancho Cucamonga just outside of the Project’s southern 

extent (USFWS 2022a). However, the area of the I-15 corridor is unlikely to support the fly’s

habitat because no Delhi Sands are mapped in the vicinity of the Project (USDA NRCS 2022). 

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6.9.2.11. Monarch Butterfly (Candidate) 

The monarch butterfly is a candidate under consideration for listing under the ESA since 

petitioning in 2014. Western monarch populations have been in steep decline over the last 20 

years (USFWS 2020). The western monarch migrates long distances to overwintering sites, 

some of which are located near the California coastline both northwest and west of the project 

area. The monarch is widespread and is known to occur in San Bernardino County. Migrating 

monarchs would pass through the study area to and from inland areas, to and to and from 

overwintering sites along the coast. Along the migratory pathway, areas of water sources have 

been shown to be important stopping locations (USFWS 2020). 

The I-15 corridor is unlikely to provide extensive support to the monarch because no known 

areas of milkweed (Asclepias spp.) obligate host plants are present, nectar sources and open 

water areas are limited, and the Project area does not provide overwintering habitat (USFWS 

2022a). 

6.9.2.12. San Bernardino Merriam’s Kangaroo Rat (Endangered) 

San Bernardino Merriam’s kangaroo rat was listed as endangered in 1998 (USFWS 1998) due to 

loss and fragmentation of habitat. Its historical range is from the San Bernardino Valley west to 

the Menifee Valley in Riverside County within coastal sage scrub habitat that forms on alluvial 

fans. The kangaroo rat is often found where it digs shallow burrows in sandy soils. It breeds 

from January through November with peak breeding in late June. The kangaroo rat does not 

need to drink water and feeds on a variety of seeds. San Bernardino Merriam’s kangaroo rat 

has been documented using areas heavily disturbed by humans, including non-native 

grasslands, margins of orchards, and out-of-use vineyards. 

Suitable habitat in Cajon Canyon and Lytle Creek may exist within the study area. The CNDDB 

reports multiple sightings of the kangaroo rat around Etiwanda Creek Wash and San Sevaine 

Canyon Wash west of the project area, and at Cajon Canyon in the vicinity of the study area. 

Suitable habitat is also present at the I-15/I-10 interchange where the alignment crosses Cajon 

Wash (CNDBB 2022). 

6.9.2.13. Desert Tortoise (Threatened) 

The desert tortoise was listed as threatened in 1990 due to a decline in population and threat 

of habitat destruction (USFWS 1994c). The tortoise can generally live in a variety of habitats in 

the Mojave and Sonoran Deserts, from sparse desert scrub to Joshua tree habitats, and in 

washes, dunes, and occasionally rocky slopes. The desert tortoise prefers to eat herbaceous 

perennial plants, annual wildflowers, and native grasses. The tortoise digs earthen burrows 

near desert shrubs or near rocks. Burrows are essential to tortoise survival. 

Suitable habitat for the desert tortoise may exist in the study area along Section 1, High Desert, 

and Section 2, Cajon Pass. 

6.9.2.14. Desert Bighorn Sheep – Clarification 

Desert bighorn sheep (Ovis canadensis nelsoni) have several subpopulations. One 

subpopulation is present in the San Gabriel Mountains and is not protected under the ESA. A 

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second subpopulation, called Peninsular bighorn sheep (Peninsular Distinct Population Unit) is 

listed as endangered under the ESA and is not in the vicinity of the Project. 

The natural range of all desert bighorn sheep includes the San Gabriel Mountains (CDFW 2020; 

Holl and Bleich 2009; Krausman 2017). Existing populations of desert bighorn sheep in the San 

Gabriel Mountains number about 300 animals and are distributed in four ewe groups 

(subgroups). The subgroup of desert bighorn sheep (Cucamonga) nearest to the study area uses 

winter and spring ranges at elevations from approximately 3,200 to 6,200 feet in the Angeles 

National Forest; the nearest area is about 5 miles west of the study area (Epps et al. 2004; Holl 

and Bleich 2009; Abella et al. 2011). 

The ESA-listed Peninsular Distinct Population Unit of desert bighorn sheep occurs in San Diego, 

Riverside, and Imperial Counties. The range of Peninsular bighorn sheep does not extend into 

the study area. 

Thus, there are no ESA-listed subpopulations of bighorn sheep likely to be present in the study 

area. 

6.10. Designated Critical Habitats 

The proposed rail alignment crosses designated critical habitat for arroyo toad, San Bernardino 

Merriam’s kangaroo rat, and southwestern willow flycatcher (Table 16). 

Table 16. ESA-Listed Species, Suitable Habitat, and Designated Critical Habitat that May Occur 

in the Project Area. 

Designated Critical Habitat Location in Study Area 

Arroyo (southwestern) toad (Anaxyrus californicus) Cajon Canyon 

Southwestern willow flycatcher (Empidonax traillii extimus) Mojave River 

San Bernardino Merriam’s kangaroo rat (Dipodomys merriami parvus) Cajon Wash and Lytle Creek 

6.10.1.1. Arroyo (Southwestern) Toad Critical Habitat 

Designated critical habitat (USFWS 2011) for arroyo toad includes a mosaic of habitats that 

provide for breeding, egg and tadpole development in aquatic sites, juvenile and subadult 

maturation, foraging, sheltering in upland terraces, and migration and dispersal corridors 

between the habitats. Because arroyo toad may travel up to 1 mile between aquatic and upland 

habitats, migration corridors are important. Arroyo toad critical habitat is mapped Cajon 

Canyon, from the I-15/SR 138 junction to northwest of the I-215/I-15 interchange (shown in 

Appendix A). 

Mapped wildlife habitat types include Valley Foothill Riparian, Desert Scrub, Riverine and Mixed 

Chaparral. Portions of existing I-15 are within the designated critical habitat in Cajon Canyon. 

Existing threats are moderate and primarily result from recreational activities, development, 

and alterations in hydrology. 

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6.10.1.2. San Bernardino Merriam’s Kangaroo Rat Critical Habitat 

Designated critical habitat (USFWS 2002c) for San Bernardino Merriam’s kangaroo rat occurs 

within the project area in Cajon Canyon, Cajon Wash, Lytle Creek, and area in North Fontana. 

Vegetation associations for the kangaroo rat includes pioneer and intermediate Riversidean 

Alluvial Fan Sage Scrub habitats where shelter and patches of suitable soils for burrowing are 

present. Existing threats are moderate and primarily result from recreational activities, 

development, and alterations in hydrology (USFWS 2002c). 

6.10.1.3. Southwestern Willow Flycatcher Critical Habitat 

Southern willow flycatcher critical habitat (USFWS 2013a) is mapped at the Mojave River where 

the I-15 corridor crosses the waterway. Territories for southwestern willow flycatcher would 

occur within Desert Riparian, Riverine, and Valley Foothill Riparian habitat types. These are 

areas dominated by native plant species with only minor amounts of invasive plant species 

present, although non-native tamarisk (Tamarix sp.) is known to provide some habitat 

elements. Threats to the critical habitat include habitat destruction from development and 

riparian vegetation die-back because of drought. 

6.10.1.4. Other Designated Critical Habitat Locations not in the Project Study Area 

Several other species have designated critical habitat which lies outside of the study area and 

would not be affected by project construction or operation. 

These include: 

• Mountain yellow-legged frog (Rana muscosa). The nearest designated critical habitat is 

north of Rancho Cucamonga, in perennial waterways in the Angeles National Forest, 

(USFWS 2006) and outside the study area. 

• Coastal California gnatcatcher. The nearest critical habitat is in the Jurupa Hills, 

approximately 5 miles southwest of the southern-most extent of the study area. 

• Western yellow-billed cuckoo (Coccyzus americanus occidentalis). The nearest designated 

critical habitat to the study area is approximately 130 miles away at the South Fork Kern 

River (USFWS 2021). 

• California condor (Gymnogyps californianus). The nearest critical habitat is at specific 

locations within the Los Padres and Sequoia National Forests more than 100 miles 

northwest of the study area (USFWS 1976). 

• Desert bighorn sheep (Ovis canadensis). As stated above, the Peninsular subpopulation of 

desert bighorn sheep (Ovis canadensis nelsoni) is listed as endangered. The nearest critical 

habitat for the Peninsular desert bighorn sheep is located in Riverside and Imperial 

Counties, south of the study area (USFWS 2009). Critical habitat for this subpopulation does 

not extend north into San Bernardino County in the project area. No desert bighorn sheep 

critical habitat is present in the study area. 

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6.11. Background Noise 

Background noise in the study area is principally generated by existing traffic along I-15. 

Generally, loudness associated with highways increases with higher numbers of trucks, overall 

traffic volume, and vehicle speed. Topography and atmospheric conditions also determine 

distance and direction of propagation of noise (FHWA 2011). 

According to the I-15 Comprehensive Corridor Study (SCAG, SANBAG, and Caltrans 2005), the 

average daily traffic on I-15 at SR 138 in the Cajon Pass area was between 110,000 and 

120,000 vehicles in 2005 and had been increasing about 2 percent a year over the 10 years 

previous. Up to double the traffic volume was projected for 2025. I-15 is the primary freight 

corridor between Los Angeles and all states to the north and east; thus, truck traffic comprises 

up to 14 percent of the vehicles. Average traffic speed is highly variable through the corridor 

with slow uphill sections (35 to 55 mph) along the up to 6 percent grade in the 5 miles leading 

to Cajon Summit, at congested interchanges, and during heavy traffic. High-end highway speeds 

(70 to 80 mph) are normal in the flatter and less congested portions of the Project, mainly 

north of Victorville. 

Existing noise levels in the Project area were measured in October and November 2021 in urban 

noise sensitive areas where human receptors would be present (Cross-spectrum Acoustics 

2022). Equivalent continuous sound (Leq) ranged from 54.5 to 76.7 BA, including both shortterm (1-hour) and long-term (24-hour) monitoring. None of the measurements was taken in 

Section 2, Cajon Pass, or in undeveloped areas adjacent to the highway. Noise levels adjacent to 

the highway in Cajon Pass would include climbing and descending lanes on the 6 percent grade 

and could be slightly higher than those recorded in the urban areas due to additional engine 

noise. 

6.12. Santa Ana Winds 

Down-slope, dry, high wind events, known as Santa Ana winds, with sustained winds in excess 

of 40 miles per hour funnel through Cajon Pass seasonally, and sometimes at extreme forces, 

such as 74 miles per hour or greater. North Fontana in the vicinity of I-15 and Lytle Creek is 

known to be affected by these extreme force wind events. The Old Fire, which burned a wide 

area across Cajon Pass including the project area, was associated with a Santa Ana wind event. 

6.13. Biological Resources Relevant to Tribes 

Government-to-government consultation has been undertaken by FRA and tribal entities that 

may be affected by the Project. Approximately eight indigenous communities historically 

occupied the region in which the Project is proposed. Habitats, plants, and wildlife of interest to 

indigenous people include those that contribute to the communities’ cumulative body of 

knowledge and to beliefs regarding relationships with the environment as well as those related 

to resource use practices. Essential practices such as hunting, fishing, trapping, and gathering 

provide food and raw materials (Berkes 1999). Stewardship of plant-wildlife connections 

beyond those covered by the federal ESA, MBTA, and BGEPA provides longevity of culturally 

important habitats, native plants, and wildlife. 

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Traditional cultural properties that are also biological resources may be present along the 

project alignment, but they have not been identified. Therefore, impacts of the Project on 

identified traditional cultural properties are not known. 

Among the multiple people indigenous to the Los Angeles Basin, San Gabriel Mountains, and 

western Mojave Desert, a wide range of plant species are harvested for multiple purposes, 

including basket weaving, art, food, medicine, and ceremonial/religious uses (Dunbar-Ortiz 

2014; Parlee and Berkes 2006; Hammett 2000; Stevens 2003). Several plant species used for 

food and materials have been managed for thousands of years by native groups using specific 

gathering techniques to maximize both harvest and sustainability (Parlee and Berkes 2006). 

Herbs, grasses, shrubs, and trees that may contribute to these traditional practices are present 

in the project vicinity . In Table 17, a sample of these plants are listed by the wildlife habitat 

type in which they may occur. 

Table 17. Plants Possibly Present in the Study Area that May Contribute to Essential Practices 

and Traditional Cultural Practices 

Wildlife Habitat Type 

in the Study Area 

Plant Scientific Name 

(Genus) 

Common Name of Plant Within the Genus 

Likely Present in the Study Area 

(Common Name) 

Joshua Tree 

Yucca Joshua tree 

Diplacus Rock monkeyflower 

Eriodictyon Narrow-leaved yerba santa 

Eriogonum Daisy 

Opuntia Prickly pear 

Chaparral 

Hesperoyucca Chaparral yucca 

Arctostaphylos Manzanita 

Ceanothus Hairy ceanothus 

Diplacus Rock monkey 

Eriodictyon Yerba santa 

Eriogonum California buckwheat 

Malosma Laurel sumac 

Muhlenbergia Scratchgrass 

Opuntia Beavertail, prickly pear 

Quercus Scrub oak 

Rhus Sugarbush 

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Prunus Hollyleaf cherry 

Sambucus Blue elderberry 

Tricostema Wooly bluecurls 

Coastal Sage Scrub 

Dipterostemon Wild hyacinth 

Hesperoyucca Chaparral yucca 

Artemisia Wild tarragon 

Salvia California sagebrush 

Chlorogalum Soap lily 

Diplacus Bush monkey flower 

Eriogonum California buckwheat 

Helianthus Hairy-leaved sunflower 

Opuntia Prickly pear 

Sambucus Blue elderberry 

Salvia Sage (black, sacred, and chia) 

Pinus One-needle pine 

Riparian and Riverine 

Salix Willows 

Plantanus Western sycamore 

Anemopsis Yerba mansa 

Juncus Rush (long-leaved, basket) 

Juglans Southern California black walnut 

Diplacus Scarlet monkeyflower 

Populus Fremont cottonwood 

Pinon-Juniper 

Pinus One-needle pine 

Juniperus California juniper 

Ceanothus Buckbrush 

Wildlife species that may contribute to essential practices occur in one or more wildlife habitat 

types present in the project vicinity and include large and small mammals in addition to 

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multiple reptiles, amphibians, and birds. A sample of these species are listed in Table 18. Large 

mammals and predators are generally restricted to areas with large habitat areas, such as 

within the San Bernardino National Forest in Section 2, Cajon Pass. Coyote, racoon, and some 

squirrels have adapted to urban habitats and are present throughout the urban portions of the 

project vicinity. 

Table 18. Wildlife Species Present in Project Vicinity that May Contribute to Essential 

Practices of Indigenous Communities 

Common Name Scientific Name: Genus and Species or Family 

Mountain lion Puma concolor 

Black bear Ursus americanus 

Bobcat Lynx rufus 

Coyote Canis latrans 

Mule deer Odocoileus hemionus 

California ground squirrel Otospermophilus beecheyi 

Desert cottontail Sylvilagus audubonii 

Brush rabbit Sylvilagus bachmani 

Black-tailed jackrabbit Lepus californicus 

California quail Callipepla californica 

Falcons, hawks, and owls Falconidae, Accipitridae, Strigidae, and Tytonidae 

Songbirds (perching birds) Passeriformes 

Hummingbirds Trochilidae 

Roadrunner Geococcyx californianus 

San Diego gopher snake Pituophis catenifer annectens 

Red-racer coachwhip snake Coluber flagellum 

California king snake Lampropeltis californiae 

California striped racer snake Coluber lateralis lateralis 

San Bernardino ring-necked snake Diadophis punctatus modestus 

South coast garter snake Thamnophis sirtalis 

Southern pacific rattlesnake Crotalus oreganus helleri 

Woodland alligator lizard Elgaria multicarinata webbii 

Great basin fence lizard Sceloporus occidentailis longipes 

Western red-tailed skink Plestiodon gilberti rubricaudatus 

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Common Name Scientific Name: Genus and Species or Family 

California horned lizard Phrynosoma coronatum 

Blainville’s horned lizard Phrynosoma blainvillii 

California toad Anaxyrus boreas halophilus 

Western spadefoot Spea hammondii 

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7. Environmental Consequences and Mitigation 

This section describes potential effects related to project construction and operation. It also 

describes potential avoidance, minimization, and mitigation measures. 

7.1. Construction Effects 

Impacts associated with construction would occur in the temporary and permanent LOD. 

Construction effects also may indirectly affect areas through generation of fugitive dust, 

construction noise, or lighting at night. The following is organized by the location of 

construction. 

7.1.1. Railway 

The Project could permanently remove areas of wildlife habitat that are potentially suitable for 

ESA-listed species. Construction of the Project may modify wildlife habitat directly and 

indirectly by affecting habitats, vegetation, and soils, and from construction-generated dust, 

noise, hydrologic modifications, facilitation of invasive species, and changes in habitat elements 

that increase or decrease populations of predators or prey species. Construction would place 

ESA-listed species at risk of direct mortality, could result in burrow and nesting habitat loss, and 

would reinforce existing barriers to wildlife movement. Areas of habitat would be directly 

impacted temporarily by construction, including designated critical habitat for San Bernardino 

Merriam’s kangaroo rat, arroyo toad, and southwestern willow flycatcher. Appendix A provides 

maps of habitat types along with the limits of disturbance showing areas of temporary impact 

on habitat types along the alignment during construction. The maps also show areas of 

designated critical habitat. 

7.1.1.1. Vegetation Disturbance 

Construction staging and stockpiling, ground disturbance (e.g., grading), and operation of heavy 

machinery may directly remove vegetation, smother it, or compact the soils such that 

vegetation can no longer persist in the short- or long-term. Changes in vegetation may result in 

loss of wildlife habitat or degradation of habitat functions. Impacts to individual plants that may 

contribute to essential practices could occur as a result of construction activities related to 

ground disturbance, such as clearing, grading, excavation, and filling, where these plants are 

present. 

Effects due to vegetation disturbance could be mitigated by timing construction activities to 

avoid nesting season and by restoration of areas temporarily disturbed during construction. 

7.1.1.2. Construction Noise 

Construction noise could temporarily affect special status wildlife. Noise impacts are typically 

indirect, although individuals can be directly affected if noise causes physical damage to an 

individual’s auditory system. Examples of noise effects on wildlife include startling, limiting an 

individual’s ability to locate prey or habitat, reducing effectiveness of intraspecies 

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communication, masking the presence of predators, and causing adults to abandon nests or 

burrows. 

Sound attenuates with distance from the source and construction noise impacts would occur 

where project-generated construction noise levels were above traffic noise levels. The loudest 

construction noise is generated when pile drivers (95 dBA for the maximum peak [dBLmax]) or 

vibratory hammers (85 dBLmax) are used. It is estimated that such levels of construction noise 

would attenuate to background levels at 5,200 feet over hard ground or ground with sparse 

vegetation. Pile-driving for bridge construction, if needed, would create noise impacts on avian, 

terrestrial and aquatic species as noise propagates in all directions including upward and 

through water. 

Noise effects may be mitigated by implementing various noise reduction strategies during 

construction. Timing activities to occur when ESA-listed species are least likely to be present is 

commonly implemented. 

7.1.1.3. Fugitive Dust 

Construction activities such as vegetation clearing and excavation would expose soils and could 

result in increased wind erosion, creating construction-generated fugitive dust. Fugitive dust 

can also result from demolition of existing structures. Fugitive dust can affect vegetation over 

an area wider than the project footprint. Generation and deposition can negatively affect plant 

physiology and may affect plant productivity. Fugitive dust can directly affect some species, as 

well as indirectly negatively affect wildlife through ingestion of dust-laden vegetation. 

Mitigation of fugitive dust during construction generally relies on reducing soil disturbance to 

the minimum amount possible; covering open soil areas when not being worked; and strategic 

use of dust suppression, such as watering for all activities. 

7.1.1.4. Hydrologic Changes 

Any construction work near or in-water could affect Riparian and Riverine habitat types through 

hydrologic disruption or through decreased water quality by increased erosion and 

sedimentation. Blockages or changes to drainage patterns may result in effects on wildlife 

habitats and associated wildlife species. 

Hydrologic changes can be reduced by minimizing the construction footprint in and near 

waterways. Implementing BMPs that address erosion and sediment control and monitoring 

those BMPs would further reduce potential effects on hydrology during construction. 

7.1.1.5. Invasive Species Facilitation 

Construction activities could introduce or spread invasive plant species to areas with native 

vegetative communities. Ground disturbing activities and operation of construction equipment 

could disperse seed of invasive plants as a result of soil movement. Changes in desert soil crust 

due to tracking and cracking by construction vehicles could loosen soils and facilitate seed 

dispersal via wind-blown soil. Weed species are adapted to soil disturbance and the abundant 

seeds are known to be readily transported by vehicles. 

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Invasive, non-native plant species can displace native plant populations and reduce wildlife 

habitat quality. Control of invasive species should be identified as an essential element of 

construction practices, which would mitigate the risk of facilitating invasive species 

establishment. 

7.1.1.6. Human Subsidized Predation 

Human “subsidized predation” refers to human activities that alter resource availability to

foraging generalist wildlife species and as a result, increase predator populations above levels 

that would occur without the human activity. The unnatural overabundance of predators is 

attributed to increased availability, for example, of perching sites, nesting sites, food, and 

water. Roadkill along transportation corridors and trash are generally the main sources of 

subsidized food sources for generalist predators. 

The presence of construction crews may unintentionally subsidize foraging generalist species, 

such as ravens, coyotes, racoons, and fox, and in turn, may temporarily increase predation on 

native species present in the study area. In Section 1, High Desert, raven populations have 

dramatically increased in recent years, at least in part due to human activities providing food, 

along with nest sites and perches. Generalist predators are known to prey on juvenile 

mammals, reptiles, amphibians, and migratory and resident birds, and increased predator 

densities could result in increased mortality of individuals. During construction, implementing a 

program that clearly prohibits activities that create food sources would mitigate this potential 

impact. 

The construction phase of the Project may modify wildlife habitat directly and indirectly. 

Wildlife habitat within the study area would experience direct temporary or permanent impacts 

related to construction of the railway. Although the duration of construction-related impacts is 

temporary, habitats may be permanently altered if they are unable to return to a 

preconstruction condition. 

7.1.1.7. Wildlife Habitats 

The analysis of impacts on mapped habitat areas demonstrated temporary impacts on habitat 

types in the study area during construction. Temporary impacts during construction would 

affect approximately 419 acres of wildlife habitat. Appendix A provides maps showing areas of 

temporary impact on habitat types along the in the study area. 

Section 1 – High Desert 

In Section 1, High Desert, several locations of Caltrans Right-of-way currently retain native 

vegetation; these are located within the limits of disturbance and would be affected by the 

Project. Table 19 provides a summary of temporary impact areas for Section 1, High Desert. 

Annual Grasslands habitat is mainly vegetated with non-native grass species and other invasive 

forbs. This habitat type often typifies areas of previously disturbed vegetation and is frequently 

mapped adjacent to I-15 in the more developed settings of the alignment. While these areas 

may have been disturbed from native habitat conditions, Annual Grasslands habitat type 

provides some level of habitat function and thus impacts on these areas were evaluated. 

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Table 19. Section 1, High Desert, Temporary Impacts on Wildlife Habitat Types 

CWHR Wildlife Habitat Type Habitat Codea 

Temporary Impact Area 

(acres) 

Alkali Desert Scrub ASC 3.93 

Annual Grassland AGS 2.63 

Barren BAR 0.16 

Desert Riparian DRI 8.19 

Desert Scrub DSC 85.70 

Joshua Tree JST 0.35 

Juniper JUN 1.94 

Mixed Chaparral MCH 0.56 

Riverine RIV 1.82 

Sagebrush SGB 8.08 

Valley Foothill Riparian VRI 0.46 

Total for Section 1 – High Desert 113.81 

a. CWHR codes are shown on the Appendix A maps. 

Riverine habitat type at the Mojave River crossing is estimated to be impacted temporarily 

during construction (1.8 acres). Associated floodplains at the Mojave River crossing support 

Desert Riparian habitat and approximately 8 acres of temporary impact during construction 

would potentially occur. Desert Riparian habitat in this location is associated with ESA-listed 

species: southwestern willow flycatcher, least Bell’s vireo, and arroyo toad. The length of time 

to restore Desert Riparian and Riverine habitat structure following disturbance is estimated to 

be 5 to 7 years, and temporary impacts might be considered permanent impacts as a result. 

Joshua Tree habitat in the vicinity of the California Aqueduct crossing in Hesperia would be 

temporarily impacted (0.35 acre) by construction. This habitat is limited in extent due to the 

urban surroundings, however this location is associated with surface water, which is very 

limited in the study area. Desert Scrub, Juniper, and Joshua Tree habitat types are known to 

support desert tortoise. Desert Scrub, Joshua Tree, and Juniper habitats are slow to recover 

following disturbance, and restoration is very difficult. Temporary impacts of approximately 

88 acres may be considered permanent if recovery would be long-term or impossible following 

disturbance to these wildlife habitats. 

Section 2 – Cajon Pass 

Table 20 summarizes temporary impact areas for Section 2, Cajon Pass. Similar to Section 1, 

desert tortoise habitat (Desert Scrub) potentially would be impacted. Approximately 83 acres of 

temporary impact on Desert Scrub may be considered long-term or permanent. Temporary 

impacts on mixed chaparral would total approximately 88 acres. Mixed Chaparral hosts a 

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diversity of avian and terrestrial wildlife that utilize it for forage and cover and during 

movements to adjacent areas for breeding. 

Table 20. Section 2, Cajon Pass, Temporary Impacts on Wildlife Habitat Types 

CWHR Wildlife Habitat Type Habitat Codea 

Temporary Impact Area 

(acres) 

Chamise-Redshank, Mixed Chaparral CRC, MCH 3.19 

Coastal Scrub CSC 5.72 

Desert Riparian DRI 0.85 

Desert Scrub, Desert Wash DSC, DSW 1.38 

Desert Scrub DSC 81.85 

Desert Wash DSW 0.17 

Mixed Chaparral MCH 87.76 

Total for Section 2 – Cajon Pass 180.91 

a. CWHR codes are shown on the Appendix A maps. 

Section 3 – Greater Los Angeles 

Approximately 124.19 acres across Section 3, Greater Los Angeles, would be affected by project 

construction. As shown in Table 21, construction would temporarily affect large areas of Desert 

Wash (43.40 acres), Mixed Chaparral (39.82 acres), and Annual Grassland (13.84 acres) habitat 

types. Temporary direct impacts would also affect Coastal Scrub habitat (9.41 acres) and 

Riverine and Valley Foothill Riparian in Cajon Wash and Lytle Creek (13.9 acres). Cajon Wash 

and Lytle Creek support ESA-listed San Bernardino Merriam’s kangaroo rat, Santa Ana River 

woolly-star, and slender-horned spineflower. The area is also designated critical habitat for San 

Bernardino Merriam’s kangaroo rat.

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Table 21. Section 3, Greater Los Angeles, Temporary Impacts on Wildlife Habitat Types 

CWHR Wildlife Habitat Type Habitat Codea 

Temporary Impact Area 

(acres) 

Annual Grassland AGS 13.68 

Barren BAR 3.78 

Coastal Scrub CSC 9.41 

Desert Wash DSW 43.40 

Mixed Chaparral MCH 39.82 

Riverine RIV 12.42 

Valley Foothill Riparian VRI 1.48 

Total for Section 3 – Greater Los Angeles 124.19 

a. CWHR codes are shown on the Appendix A maps. 

7.1.1.8. ESA-Listed Species 

Suitable habitat for ESA-listed species is assumed to be present within the study area. Focused 

presence/absence surveys have not been performed to confirm presence of ESA-listed species 

within the study area. Preconstruction surveys are planned, and project mitigation measures 

would be further identified to reduce the extent and/or magnitude of impacts for the Project. 

Section 1 – High Desert 

Project construction around and over the Mojave River in Section 1, High Desert, may affect 

desert tortoise, southwestern willow flycatcher, western yellow-billed cuckoo, and least Bell’s 

vireo (Table 22). Critical habitat for southwestern willow flycatcher mapped in the vicinity of 

the Mojave River could be directly affected by construction activities. 

Table 22. ESA-Listed Species Potentially Affected in Section 1, High Desert 

Common Name Scientific Name Status Under ESA Effects Determination 

Least Bell's vireo Vireo bellii pusillus Endangered May Affect, Not Likely to 

Adversely Affect 

Southwestern willow flycatcher Empidonax traillii extimus Endangered May Affect, Not Likely to 

Adversely Affect 

Western yellow-billed cuckoo Coccyzus americanus 

occidentalis 

Threatened May Affect, Not Likely to 

Adversely Affect 

Desert tortoise Gopherus agassizii Threatened May Affect, Not Likely to 

Adversely Affect 

Construction activities (e.g., grubbing, grading, excavation, and driving off-road) could cause 

direct mortality of individuals of special status species, as heavy equipment could crush smaller 

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animals. Construction activities could destroy active nests, burrows, or young, if construction 

occurs during a species’ nesting or rearing season—potentially reducing species numbers and 

distribution of genetic material and resulting in long-term effects. Indirect mortality could result 

from a decrease in the suitability and stability of burrows for desert tortoise. 

Riverine habitat type at the Mojave River crossing was estimated to be impacted temporarily 

during construction (1.8 acres). Associated floodplains at the Mojave River crossing support 

Desert Riparian habitat; approximately 8 acres of temporary impact during construction would 

potentially occur in those floodplains. Desert Riparian habitat at the Mojave River crossing is 

associated with three ESA-listed species: southwestern willow flycatcher, least Bell’s vireo, 

western yellow-billed cuckoo, and arroyo toad. Riparian habitats often support plants, such as 

rush and cattail, used for essential practices by indigenous people, and these areas may be 

disturbed during construction. The length of time to restore Desert Riparian and Riverine 

habitat structure following disturbance is estimated to be 5 to 7 years, and temporary impacts 

might be considered permanent impacts as a result. 

Preconstruction presence/absence protocols surveys would be used to confirm suitable habitat 

and if needed presence of southwestern willow flycatcher, western yellow-billed cuckoo, and 

least Bell’s vireo. Several project mitigation measures would reduce the likelihood of effects, 

including avoiding vegetation disturbance during the nesting season and restoration of 

vegetated areas temporarily disturbed during construction. 

Section 2 – Cajon Pass 

In Section 2, Cajon Pass, construction activities may affect southwestern willow flycatcher, 

desert tortoise, least Bell’s vireo, and arroyo toad (Table 23). 

Table 23. ESA-Listed Species Potentially Affected in Section 2, Cajon Pass 

Common Name Scientific Name Status Under ESA 

Preliminary Effects 

Analysis 

Arroyo (southwestern) toad Anaxyrus californicus Endangered May Affect, Likely to 

Adversely Affect 

Least Bell's vireo Vireo bellii pusillus Endangered May Affect, Likely to 

Adversely Affect 

Southwestern willow flycatcher Empidonax traillii extimus Endangered May Affect, Likely to 

Adversely Affect 

Desert tortoise Gopherus agassizii Threatened May Affect, Not Likely to 

Adversely Affect 

Construction impacts in Section 2, Cajon Pass, would be similar in nature to those described 

above for Section 1, High Desert. Due to its nature, location, and duration, construction would 

likely adversely affect arroyo toad. Critical habitat for arroyo toad in the vicinity of Cajon 

Canyon would be directly affected by construction activities, which could potentially be an 

adverse effect. 

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Preconstruction surveys of habitat suitability and if needed presence/absence protocols surveys 

would be used to confirm presence of southwestern willow flycatcher, least Bell’s vireo, and 

arroyo toad in Section 2. 

Section 3 – Greater Los Angeles 

Work over and around Cajon Wash in Section 3, Greater Los Angeles, may affect San 

Bernardino Merriam’s kangaroo rat, slender-horned spineflower, and Santa Ana River 

woolly-star (Table 24). Interchange ramp modifications south of Cajon Wash may affect least 

Bell’s vireo, coastal California gnatcatcher, arroyo toad, and San Bernardino Merriam’s 

kangaroo rat. 

Table 24. ESA-Listed Species Potentially Affected in Section 3, Greater Los Angeles 

Common Name Scientific Name Status Under ESA 

Preliminary Effects 

Determination 

San Bernardino Merriam’s 

kangaroo rat 

Dipodomys merriami parvus Endangered May Affect, Likely to 

Adversely Affect 

Arroyo (southwestern) toad Anaxyrus californicus Endangered May Affect, Likely to 

Adversely Affect 

Slender-horned spineflower Dodecahema leptoceras Endangered May Affect, Likely to 

Adversely Affect 

Santa Ana River woolly-star Eriastrum densifolium ssp. 

sanctorum 

Endangered May Affect, Likely to 

Adversely Affect 

Least Bell's vireo Vireo bellii pusillus Endangered May Affect, Likely to 

Adversely Affect 

Coastal California gnatcatcher Polioptila californica californica Threatened May Affect, Not Likely 

to Adversely Affect 

San Bernardino Merriam’s kangaroo rat is assumed to be present in the study area in suitable 

habitat. Construction-related activities could result in injury or mortality to individuals of the 

species if construction equipment crushed or trapped them in their burrows or removed 

foraging habitat or habitat linkages. 

Development in areas surrounding the Project have previously altered the historic fluvial flow 

patterns and scouring regimes of Lytle Creek and Cajon Wash, disrupting the natural flood 

regime in the area. As a result, critical habitat functions have been disrupted to some extent. 

The most recent observations of slender-horned spineflower very near the study area occurred 

at Lytle Creek in 1994. No recent observations were listed in the database (CNDDB 2022, CNPS 

2022). 

Rare plant surveys in alluvial fan areas that would be crossed by the Project and that may 

support slender-horned spineflower and Santa Ana River woolly-star would confirm if the 

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species are present. If presence is confirmed, actions to prevent disturbance could be 

implemented. 

Populations of Santa Ana River woolly-star and coastal California gnatcatcher have been 

observed in the vicinity of the study area. Construction-related activities could result in injury or 

mortality to individuals of these species if individuals were within the limits of construction. 

Fugitive dust from construction could negatively affect woolly-star or slender-horned 

spineflower in or near the construction area. Construction noise may disturb gnatcatcher 

individuals in or near the construction areas. 

Trapping surveys for San Bernardino Merriam’s kangaroo rat prior to construction would be 

needed to confirm presence or absence of this species in the Project area. Rare plant surveys 

for slender-horned spineflower and Santa Ana River woolly-star, as well as presence/absence 

protocols surveys, may be implemented prior to construction to confirm presence ESA-listed 

species. 

7.1.1.9. Critical Habitats 

As stated, construction would occur within designated critical habitat for arroyo toad, San 

Bernardino Merriam’s kangaroo rat and southwestern willow flycatcher. Construction activities 

would likely adversely affect these three critical habitat areas due to the location and duration 

of the disturbance. Preconstruction field evaluations would verify if essential physical and 

biological features are present to support these species, and how these elements would be 

impacted by the Project. 

7.1.1.10. Effects on Bald and Golden Eagles 

As stated, golden eagles have been reported foraging in Cajon Canyon and seen near the 

Mojave River and Glen Helen Regional Park, but active nesting sites are not known to be 

present in the near vicinity (CNDDB 2022; eBird 2022). Bald eagles are known to forage at Glen 

Helen Regional Park in the project vicinity (eBird 2022), and thus are inferred to forage within 

the project area due to proximity. 

Construction activities may disturb nesting bald and golden eagles, if nests or foraging birds are 

present within the study area. Noise and construction activities may cause eagles to avoid 

foraging in the area. 

7.1.1.11. Effects on Migratory Birds 

Trees, shrubs, and cacti present in the various habitat types in the study area provide suitable 

nesting and resting habitat for migratory birds. If construction occurs during the migration or 

breeding season, migratory birds could be disturbed by construction activities and related 

noise. Cajon Pass and the Mojave River provide key habitat areas during migration for resting. 

Construction could disturb the nesting and foraging of migratory birds. 

Project construction may temporarily increase noise, causing migratory species to avoid these 

key areas. Construction activities (e.g., clearing, grading, excavation, pile driving) and loss of 

habitat elements such as cover could affect migratory birds. As a result, birds may abandon 

nests, causing subsequent loss of eggs or young at active nests. 

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Construction effects on migratory birds would be mitigated by implementation of timing that 

prohibits disturbance to vegetation during nesting season and avoidance of the initiation of 

ground disturbance or pile driving during the nesting season. 

7.1.1.12. Wildlife Corridors 

Indirect impacts on wildlife movement could occur where railway construction temporarily 

blocks existing wildlife migration corridor underpass(es). Construction activities that would 

prevent wildlife from moving through the area are anticipated to occur over approximately 

18 months in any single location. 

7.1.1.13. Conservation Areas 

Direct permanent effects on conservation areas are not anticipated to occur. The Project would 

be constructed within the existing Caltrans right-of-way, where no conservation areas are 

present. Construction activities would not result in permanent changes to access to 

conservation areas. Construction would not affect quality or quantity of plant resources 

available for essential practices in conservation areas. 

Temporary indirect effects may occur to conservation areas that are near enough to be affected 

by construction noise. Pile-driving noise may affect wildlife in those areas. Construction noise 

could result in wildlife avoiding the area for the duration of construction, which would 

potentially reduce the availability of wildlife resources for essential practices on conservation 

lands. Pile-driving could occur over 12 to 18 months in any location where required for 

construction. 

7.1.2. Hesperia Station 

Construction of the Hesperia station would occur in an urban environment. Limited areas of 

urban wildlife habitat currently occur in the vicinity of the proposed station. The passenger 

loading platform would be in the I-15 median, however the station supporting facilities and 

parking area would be developed on lands that have been previously disturbed by 

development. No suitable habitat for any ESA-listed species occurs in the location of the station 

or vicinity. No designated critical habitats are in the vicinity of the station and no ESA-listed 

species have been reported to occur in the vicinity. Therefore, construction would not have 

direct or indirect effects on wildlife habitats, ESA-listed species, or critical habitat. 

7.1.3. Rancho Cucamonga Station 

The Rancho Cucamonga station would be constructed in an existing urban environment. 

Limited areas of urban wildlife habitat currently occur in the vicinity of the proposed station. 

There are no suitable habitats for any listed species at the station location. Given the nature of 

the site as an existing rail corridor and commuter rail station and its parking area and the lack of 

suitable habitat, listed species are unlikely to be present at this site. Therefore, construction 

would not have direct effects on wildlife habitats ESA-listed species or designated critical 

habitats. 

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7.2. Operational Effects 

Based on this preliminary evaluation, the Project operations would affect wildlife habitats. .The 

Project would convert habitat within the project footprint transportation use and would likely 

remove areas of habitat suitable for ESA-listed species. Rail operations could result in bird 

strikes, which could include ESA-listed bird species, migratory birds, and raptors and protected 

eagles. 

7.2.1. Railway 

7.2.1.1. Noise Effects 

Operation of the railway in the highway median was shown to not increase noise levels above 

the existing highway noise along the alignment (Cross-Spectrum Acoustics 2022). For 

median-running rail, operational noise would generally occur within the extent of the existing 

developed highway. No noise modeling was performed for wildlife receptors. However, 

sensitive species may startle at passing train noise.. San Bernardino Merriam’s kangaroo rats 

communicate by foot-drumming, arroyo toads call to attract mates, and avian species have 

nesting territories that males defend with songs; any of these species could be directly affected 

by HSR noise that masks or alters the effectiveness of these communication modes. Noise 

avoidance results in reduced habitat suitability and/or habitat area for species and may reduce 

the ability to migrate. 

7.2.1.2. Change in Ignition Sources 

Powerline failure, often due to high winds, has been demonstrated across California to be 

instrumental in providing ignition sources to wildfires, which would indirectly affect biological 

resources. The Project would construct new powerlines on catenary structures to provide 

traction power to power trains in a known high wind area. Changes in wildlife frequency or 

intensity can alter wildlife habitats through changes in species composition or alterations in 

structures and may result in loss of suitable habitat. 

The project design would include automatic power shutoff and other safety features that would 

work to cut power and prevent powerline failures from becoming ignition sources. Median 

running rail would be isolated from ignition sources by adjacent freeway infrastructure. With 

these measures, the Project would be unlikely to provide ignition sources to wildfires. 

7.2.1.3. Wildlife Corridors 

Linear transportation corridors are known to limit wildlife movement by blocking safe passage 

across landscapes. I-15 is an existing barrier to local and regional wildlife movement across the 

landscape throughout the proposed project alignment. Because the rail line is aligned with I-15, 

the Project would widen this existing linear transportation corridor in locations where the 

highway lanes would be widened to accommodate median-running rail. This would reinforce 

the blockage of wildlife movement in areas where no suitable over or under crossing was 

present. 

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Operation of HSR would produce a new noise source at existing wildlife crossings. For 

median-running rail, operational noise would generally occur within the extent of the existing 

developed highway. The existing environment is already noisy because of highway traffic and 

heavy rail operations, and it is not known if the additional intermittent noise of passing highspeed trains during operations would cause wildlife to avoid using the existing underpass or 

culvert crossings. 

Impacts on wildlife movement could be mitigated by well-placed and well-designed wildlife 

crossings that, coupled with fencing, would allow for safe passage and landscape connectivity 

for terrestrial wildlife. Both underpass and overpass wildlife crossings are often needed to 

create wildlife corridors for the diversity of wildlife species. The Project would be largely 

median running and would install new bridges and culvert crossings in-line with those already 

existing on I-15, no new exclusive wildlife crossings are planned by the Project. 

7.2.1.4. Invasive Species Effects 

Operational landscaping and maintenance in the study area following construction would be 

focused on avoiding invasive seed dispersal, controlling existing invasive plant populations, and 

restoring areas with native vegetation to reduce potential impacts of invasive species to wildlife 

and native plant communities. 

7.2.1.5. Wildlife Strikes 

Trains traveling up to 140 mph through the I-15 corridor would increase the likelihood of avian 

strikes along the corridor, particularly in areas where birds are abundant. A study recording 

bird-high-speed train collisions demonstrated an average mortality rate of 60 birds per 

kilometer (about 96 birds per mile) per year for all bird species when operation frequency was 

53 trains per day (García de la Morena 2017). The study also showed that approximately 

38 percent of bird crossings were of birds resting on some element of the infrastructure 

moments prior to arrival of the train. The study was based on filming and only included daylight 

hours, so an estimate of strikes during nighttime was not made. 

For the Proposed Action, it is not known if the location of proposed rail infrastructure in the 

highway median would attract birds resting while attempting to cross the highway, thus 

increasing the number of birds within striking distance, or if the highway itself would reduce the 

likelihood of perching on rail infrastructure. Based on the 2017 study, it appears bird strike 

mortalities are likely; however, the number of strikes may differ significantly in magnitude from 

the study due to the different environmental, infrastructure, and operating conditions of the 

Proposed Action from the study’s conditions. 

For all at-grade portions of the alignment, exclusion fencing would be constructed parallel to 

the rail line for safety to terrestrial wildlife. However, this safety step could also inadvertently 

trap wildlife that may have gained access to the rail corridor, potentially increasing the risk of 

wildlife strikes. Operation of HSR could result in terrestrial wildlife mortality through collisions. 

Collisions could occur to any wildlife that gain access to the path of the train, or to wildlife that 

attempt to cross the corridor, entering the highway but are not able to cross the rail alignment 

due to the high-speed rail fencing at the median. By converting the I-15 median from natural 

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substrate, the Project may remove access to “rest” habitat for wildlife attempting to cross I-15 

and the project corridor possibly causing increased wildlife mortality. 

7.2.1.6. Human Subsidized Predation 

During project operations, human subsidized predation could occur due to activities that may 

inadvertently provide food and/or shelter to generalist predators. The Project’s catenary

system could add perch locations that may be used by avian predators, such as ravens, which 

may increase predation of special status species. 

Train strikes of avian and terrestrial species could increase supply of carrion to generalist 

predators and support larger populations. Increased predators may add predation pressure to 

prey species in the area, such as desert tortoise. 

During operations, maintenance of the railway alignment to reduce subsidies (e.g., trash 

pickup, removal of mortalities, fence maintenance, and maintaining bird exclusion from using 

catenary) and at passenger stations (e.g., trash collection) will be important. Implementing 

strong, wind-proof, covered trash collection areas, will be important to reduce subsidized 

predation at passenger stations. A regular maintenance program that identifies, implements, 

and reinforces good housekeeping would mitigate the potential indirect effect of human 

subsidized predation. During operations, any identified perching and nesting locations would be 

modified to make them no longer suitable (bird exclusion). 

7.2.1.7. Permanent Effects on Wildlife Habitats 

The analysis of impacts on mapped habitat areas demonstrated permanent impacts on habitat 

types in the study area. Appendix A provides maps of habitat types along with the limits of 

disturbance showing areas of permanent impact on habitat types along the alignment. 

As stated, many areas within the Caltrans right-of-way have been altered from natural 

vegetation community composition by previous disturbance; these areas are generally mapped 

as Urban habitats (see Appendix A). The Build Alternative would retain these types of 

developed and disturbed surfaces, resulting in no change to the quality or function of the Urban 

habitat type. 

Approximately 64 acres of wildlife habitat types would be permanently converted to 

transportation uses by the Project. Effects on wildlife habitats are further described in more 

detail in the following. 

Section 1 – High Desert 

In Section 1, High Desert, several locations of Caltrans right-of-way retain native vegetation, 

these are located within the permanent LOD and would be permanently removed by the 

Project. 

Table 25 summarizes the permanent impact area, by CWHR habitat type for Section 1. 

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Table 25. Section 1, High Desert, Areas of Permanent Impacts on Wildlife Habitat Types 

CWHR Wildlife Habitat Type Habitat Codea 

Permanent Impact Area 

(acres) 

Alkali Desert Scrub ASC 0.54 

Annual Grassland AGS 2.36 

Desert Riparian DRI 0.94 

Desert Scrub DSC 28.41 

Juniper JUN 0.88 

Riverine RIV 0.73 

Sagebrush SGB 13.58 

Total for Section 1 – High Desert 47.80 

a. CWHR codes are shown on the Appendix A maps. 

Estimated direct permanent impacts on wildlife habitat in Section 1, High Desert, total 

approximately 48 acres, with most of the permanent impact on Desert Scrub habitat. Desert 

Scrub and Juniper habitat types are also known to support desert tortoise and the area of 

habitat reduction for these two habitats is estimated to be approximately 30 acres. Areas of 

Sagebrush habitat would be permanently reduced by approximately 14 acres. Sagebrush in the 

area supports a variety of wildlife species. Riverine and Desert Riparian habitat types at the 

Mojave River crossing are estimated to be impacted by permanent impacts of approximately 

1.7 acres. The Mojave River area is known to support ESA-listed wildlife including southwestern 

willow flycatcher, least Bell’s vireo, western yellow-billed cuckoo, and arroyo toad and is 

mapped as designated critical habitat for southwestern willow flycatcher. Monarch butterflies 

use riparian areas for nectaring due the diversity of plants that may be in bloom at any time, 

and may use riparian area for breeding, if milkweed host plants are present. 

Section 2 – Cajon Pass 

Table 26 summarizes permanent impacts for Section 2, Cajon Pass. Estimated direct permanent 

impacts on wildlife habitat total approximately 15 acres, with most of the permanent impact on 

Desert Scrub habitat (8.22 acres). Desert Scrub supports desert tortoise and, when Desert Scrub 

occurs adjacent to suitable riparian habitat, may support adult and immature arroyo toads for 

burrowing and foraging. Areas of Mixed Chaparral habitat would be permanently reduced by 

approximately 6 acres. No wildlife are known to obligately use Mixed Chaparral, but a wide 

variety of wildlife use Mixed Chaparral for cover, forage, and travel to adjacent habitats. 

Table 26. Section 2, Cajon Pass, Areas of Permanent Impacts on Wildlife Habitat Types 

CWHR Wildlife Habitat Type Habitat Codea 

Permanent Impact Area 

(acres) 

Barren BAR 0.63 

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Coastal Scrub CSC 0.15 

Desert Scrub DSC 8.22 

Mixed Chaparral MCH 6.16 

Total for Section 2 – Cajon Pass 15.17 

a. CWHR codes are shown on the Appendix A maps. 

Section 3 – Greater Los Angeles 

Estimated direct permanent impacts on wildlife habitat in Section 3, Greater Los Angeles, total 

approximately 1 acre, with most of the permanent impact on Desert Wash habitat (0.59 acre). 

Desert Wash habitat supports San Bernardino Merriam’s kangaroo rat, coastal California 

gnatcatcher, Santa Ana River woolly-star, and slender-horned spineflower in this location. The 

area is also mapped as designated critical habitat for San Bernardino Merriam’s kangaroo rat. 

Areas of Mixed Chaparral habitat would be permanently reduced by approximately 0.3 acre. 

Table 27 provides a summary of impact areas for Section 3, Greater Los Angeles. 

Table 27. Section 3, Greater Los Angeles, Areas of Permanent Impacts on Wildlife Habitat 

Types 

CWHR Wildlife Habitat Type Habitat Codea 

Permanent Impact Area 

(acres) 

Annual Grassland AGS 0.05 

Coastal Scrub CSC 0.03 

Desert Wash DSW 0.59 

Mixed Chaparral MCH 0.29 

Total for Section 3 – Greater Los Angeles 0.96 

a. CWHR codes are shown on the Appendix A maps. 

7.2.1.8. Critical Habitats and ESA-Listed Species 

Operation of the rail line would occur adjacent to critical habitat for arroyo toad, San 

Bernardino Merriam’s kangaroo rat, and southwestern willow flycatcher. Operation of the rail 

line would not directly affect adjacent designated critical habitat. 

Indirect effects such as train noise and human-subsidized predation effects would occur to any 

wildlife adjacent to the rail line or utilizing designated critical habitat adjacent to the rail line 

during operations. Wildlife strikes of avian species by trains during operations is possible and 

could result in loss of protected animals. Protected avian species that could be lost due to 

strikes include coastal California gnatcatcher, least Bell’s vireo, and southwestern willow 

flycatcher. 

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7.2.1.9. Effects on Migratory Birds 

Operational effects on migratory birds could be direct if avian species use new structures in the 

rail corridor for nesting or foraging and bird strikes occur. HSR avian mortalities haves been 

studied recently, and strikes were demonstrated to occur (García de la Morena 2017). 

Migratory birds could be present during operations and would be subject to strikes by 

operating trains if they crossed or utilized the rail corridor. Indirect impacts may occur to 

migratory birds in areas adjacent to the corridor due to increased noise, causing migratory 

species to avoid these areas. As a result of train noise, birds may avoid adjacent areas causing a 

reduction in suitable nesting areas. 

7.2.1.10. Effects on Bald and Golden Eagles 

Operational effects on raptors would be similar to effects on migratory birds. If raptors were to 

use new structures for nesting resulting in increased risk of strikes or if increased supply of 

carrion supply in the rail corridor attracted raptors, then raptor mortality could increase. In 

contrast to increased presence of raptors, operational train noise may cause raptors to avoid 

the rail line and the adjacent area. 

7.2.1.11. Effects on Conservation Areas 

Project operation would not change access to resources in conservation areas for essential 

practices to indigenous communities. Operation of HSR in the I-15 corridor would have no 

direct effects on conservation areas. 

Operational noise would be present, but, throughout the median-running alignment, 

operational noise is assumed to be subsumed into the existing highway noise and, thus, would 

not affect noise levels at any conservation area within 1 mile of the Project. 

7.2.2. Hesperia Station 

Because the Hesperia station would operate in a largely urban environment, operational effects 

of the passenger station would not directly affect wildlife habitats, ESA-listed species, or critical 

habitats because noise and other human-influenced activities already occur in this area. 

Operation of the station would have no effect on migratory birds or eagles. Station operation 

may indirectly affect native wildlife and vegetation by facilitating invasive species and 

supporting human subsidized predation. 

7.2.3. Rancho Cucamonga Station 

The Rancho Cucamonga station would operate in a developed, urban environment. Operational 

effects of the passenger station would not directly affect wildlife habitats, ESA-listed species, or 

critical habitats because noise and other human-influenced activities already occur in this area. 

Operation of the station would have no effect on migratory birds or eagles. Indirect effects of 

station operation, such as human subsidized predation, may occur. 

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7.3. Cumulative Effects 

The Project, in combination with other past, present, and reasonably foreseeable future 

actions, would convert undeveloped areas to developed ones, resulting in habitat loss, 

fragmentation, and potentially associated loss of common and special status plant and animal 

species. 

The Project would potentially facilitate development pressure in the Apple Valley planning area 

(City of Apple Valley) and the Desert Planning area (City of Victorville) surrounding the final 

5 miles of the alignment and project terminus, where demand for commuter and recreational 

access to HSR transportation would increase as result of a new transportation element 

provided by the Project. The Apple Valley and Desert planning areas are currently largely 

undeveloped, and their development would result in loss of habitat supporting common and 

special status plants and animal species. 

The town of Apple Valley is developing a multispecies HCP to guide development at a landscape 

level for the Apple Valley planning area in the vicinity of the project terminus. However, there 

does not appear to be a parallel planning effort for the Desert planning area of Victorville. 

Planning elements could be identified to mitigate cumulative effects, for example, by 

identifying conservation areas and protecting viable habitat linkages (Apple Valley 2022). 

Combined with the effects of future development, effects of the Project may further reduce the 

suitability of remaining habitat to support listed species, San Bernardino Merriam’s kangaroo

rat, coastal California gnatcatcher, slender-horned spineflower, and Santa Ana River woolly-star 

in the vicinity of Section 3, Greater Los Angeles. In this area, the North Fontana Conservation 

Program has identified conservation actions that work to protect and mitigate development on 

Riversidean Alluvial Fan Sage Scrub and Riversidean Sage Scrub habitats, thereby providing 

support to these wildlife habitats and associated species. Future development would be 

required to comply with the action plan and implementation plan developed under the 

conservation program, thus mitigating some cumulative effects. 

Implementation and development of conservation and mitigation approaches could reduce 

cumulative effects on habitats and plant and animal species. Preserving and conserving wildlife 

habitats and other biological resources that may be affected by future development would help 

to reduce cumulative effects on biological resources. 

7.4. Impact Avoidance and Minimization Measures 

Practicable measures to avoid impacts on threatened and endangered species and their critical 

habitats, such as those described below, will be implemented by the Project. In areas where 

unavoidable impacts may occur, efforts will be made to minimize those impacts. Following 

implementation of avoidance and minimization measures, the Proposed Action will employ 

compensation measures to offset any unavoidable impacts that occur. 

The following are proposed mitigation measures for the Proposed Action. The general 

measures are followed by additional measures for specific species. 

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More detailed Habitat Restoration Plan discussing soil and vegetation restoration following 

temporary construction disturbance at specific areas, and detailed Translocate Plans for San 

Bernardino Kangaroo Rat are provided under separate cover. 

7.4.1. General Measures 

Areas of Concern During Construction 

Biologists shall be present for construction activities along the following portions of the Project 

alignment: 

• Mojave Desert vicinity: From the northern-most Project extent, continuing south to the I-15 

Bridge over D/E Street in Victorville 

– Focusing on protection of southwestern willow flycatcher, monarch butterfly, 

least Bell’s vireo, western yellow-billed cuckoo, and critical habitat for 

southwestern willow flycatcher. 

• Cajon Canyon and Cajon Summit vicinity: From I-15 at Oak Hill Road to I-15 at Hall Ranch 

Road 

– Focusing on protection of southwestern willow flycatcher, least Bell’s vireo, 

monarch butterfly, arroyo toad, and critical habitat for arroyo toad. 

• Cajon Wash and Lytle Creek vicinity: From I-15 at Hall Ranch Road to I-15 at Summit Avenue 

– Focusing on protection of San Bernardino Merriam’s kangaroo rat, coastal 

California gnatcatcher, ESA-listed plants, monarch butterfly, and critical habitat 

for San Bernardino Merriam’s kangaroo rat. 

Note that monarch butterfly, a candidate species for listing under ESA, may be present in any 

portion of the Project area during nine months of the year. 

No biologist is required during construction along portions of the alignment not listed above—

for example, in urban areas of Rancho Cucamonga, Hesperia, and Victorville—although the 

Applicant and its contractors may choose to utilize resource monitors/biological monitors at 

their discretion in these areas to ensure environmental compliance. 

Avian Avoidance - Exclusion Areas and Timing 

Certain types of construction activities are not to be commenced during bird breeding season at 

three separate locations along the alignment. The types of construction activities regulated are 

pile driving and ground disturbance (defined below). This avoidance mitigation measure does 

not apply to other construction activities or other locations. 

Three separate locations of Avian Avoidance Exclusion Areas are as follows: 

• Area 1. Mojave River 

• Area 2. Cajon Wash 

• Area 3. Lytle Creek 

Pile driving and ground disturbance activities are prohibited in the Avian Avoidance Exclusion 

Areas during closure dates, unless the work is initiated prior to the start of the closure period. 

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Project-related ground disturbance is defined as: 

• Vegetation removal, including clearing and grubbing of vegetation, 

• Site preparation including grading and establishment of construction access, or 

• Grading, earth moving, stockpiling materials, excavation, and filling activities. 

Table 28 summarizes the closure dates for the three Avian Avoidance Exclusion Areas. 

Table 28. Avian Avoidance Exclusion Areas and Closure Dates 

Closure Dates 

Location From To 

Area 1. Mojave River Crossing March 15 September 30 

Area 2. Cajon Wash February 15 September 30 

Area 3. Lytle Creek February 15 6HSWHPEHU

Conduct Mandatory Environmental Awareness Training Program 

All Project staff, including Applicant, contractors, operators, consultants, field personnel, and 

subcontractors, shall attend a mandatory environmental awareness training program. The 

program will be developed and presented by knowledgeable biologists. 

The curriculum shall cover the following, at a minimum: 

• Awareness information for each ESA-listed species potentially present and designated 

critical habitats in the Project area 

• The legal protection for each ESA-listed species, critical habitats, and the definition of “take” 

for listed species 

• Measures to protect ESA-listed species during construction 

• Review of the Project’s environmental commitments, restoration steps, and mitigation 

requirements 

• Explanation of the reasoning behind the restrictions on the construction, where restrictions 

exist 

• Importance of avoiding ground-disturbing activities outside the designated work areas, 

closing construction gates, and visually surveying designated work zones prior to moving 

equipment 

• Requirements for ground and general areas inspection prior to moving vehicles and 

equipment 

• Explanation of the problem of generalist predators, such as common ravens (Corvus corax) 

• Explanation of the importance of keeping construction areas free from trash and litter and 

avoiding subsidizing generalist predators 

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• Penalties for violation of federal and state environmental laws 

Training shall be documented, including names of trainees and dates of completion. All trained 

workers will be given an identifying sticker to be worn on site. 

Plan for and Conduct Biological Monitoring during Construction 

At least 60 days prior to the start of Project-related ground disturbance that would occur within 

200 feet of any occupied ESA-listed habitat or within suitable habitat within any designated 

critical habitat area, a written Biological Monitoring Plan (Plan) shall be developed for approval 

by USFWS. 

The Plan shall discuss the type, locations, and timing of physical disturbance: (1) within 400 feet 

of any occupied ESA-listed species habitat, or (2) within suitable habitat within designated 

critical habitat areas. 

The Plan will identify appropriate monitoring and reporting needs, including responsibilities, 

timing, and monitoring activities, and will identify coordination requirements, safety 

requirements, and communications, including points of contact. The Plan shall be implemented 

during construction to ensure compliance with environmental commitments and will focus on 

commitments under the ESA. 

Reporting 

No more than 90 days after the completion of construction, the biologist(s) shall prepare a 

monitoring, restoration, and mitigation report for submission to USFWS for any construction 

areas: (1) within 400 feet of any occupied ESA-listed species habitat, or (2) within suitable 

habitat within designated critical habitat areas. The report will include the results of 

construction monitoring, photographs, and the type and locations of installed mitigation and 

restoration measures. 

Photographs 

Pre- and post-construction photographs shall be taken to document habitat conditions and 

alterations within the limits of disturbance during construction activities. Photographs will be 

dated, their locations recorded, and will be stored in a manner that will allow access for 

reporting purposes. 

Designated Work Areas 

In areas adjacent to sensitive resources, the contractor shall restrict all work to designated 

work areas through the use of visible demarcation. 

The following are locations of sensitive resources: 

• Mojave Desert vicinity: From the northern-most Project extent, continuing south to the I-15 

Bridge over D/E Street in Victorville 

• Cajon Canyon and Cajon Summit vicinity: From I-15 at Oak Hill Road to I-15 at Hall Ranch 

Road 

• Cajon Wash and Lytle Creek vicinity: From I-15 at Hall Ranch Road to I-15 at Summit Avenue 

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The contractor shall avoid any unauthorized disturbance of native vegetation and sensitive 

resources outside the designated work area. Remnant habitat and existing stands of native 

vegetation will be identified and protected wherever possible. 

During construction, the biologist, or their representative, shall inspect visible demarcation and 

shall help ensure that construction equipment, vehicles, and associated activities remain within 

designated construction work areas. 

Noxious Weed Management During Construction 

A noxious weed survey shall be performed prior to ground-disturbing activities. During and 

following construction, the contractor shall avoid the introduction or spread of noxious weeds 

by performing weekly inspections and weed removal/control. 

Avoid Injury to Wildlife 

Supplies, equipment, and/or construction excavations where wildlife such San Bernardino 

Merriam’s kangaroo rat, and/or other wildlife could hide (e.g., materials stockpiles, equipment 

in staging areas, and under vehicles) shall be inspected by all construction crew members prior 

to moving or working on or with them to avoid killing or injuring wildlife. If wildlife is detected, 

the biologist shall be contacted. 

Preserve Biological Material 

The contractor and Applicant shall preserve any dead biological material encountered related 

to endangered species in the best possible state for later analysis. Preservation may include 

chilling and general protection from disturbance. USFWS will provide instruction regarding the 

final disposition of the carcass(es). 

Prepare and Implement a Temporary Erosion and Sediment Control Plan 

The contractor shall prepare and implement a Temporary Erosion and Sediment Control Plan 

that identifies best management practices (BMPs) best suited for site conditions. The plan shall 

meet applicable Caltrans standards. 

Implement Spill Prevention, Control, and Countermeasures Plan 

The contractor shall develop and implement a Spill Prevention, Control, and Countermeasures 

Plan for construction activities. The potential for chemical spills or releases of contaminants, 

including any non-stormwater discharge to drainage channels, shall be managed and the risk 

reduced. If a spill occurs, cleanup, containment, and response measures shall be implemented. 

Any accidental spills will be immediately contained and reported to the California Office of 

Emergency Services (1-800-852-7650) and the National Response Center (1-800-424-8802). 

No Storage of Construction Equipment or Materials within the 100-Year Floodplain 

The contractor shall not store construction equipment, chemicals, fuels, or lubricants within the 

100-year floodplain of any water feature. 

Equipment Maintenance and Refueling only in Designated Areas 

All equipment maintenance and dispensing of fuel, oil, coolant, or any other such activities will 

be restricted to the designated staging areas outside of the Mojave River floodplain, Cajon 

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Wash, and Lytle Creek to prevent the release of hazardous substances into these sensitive 

areas. 

Fugitive Dust Control Plan 

The contractor shall develop and implement a Fugitive Dust Control Plan that includes, at a 

minimum, the following: 

• Reduce nonessential earth-moving activity under high-wind conditions when visible dusting 

occurs from surfaces due to wind erosion. 

• Water shall be used for stabilization of surfaces for fugitive dust control within 400 feet of 

areas occupied by ESA-listed species, or within suitable habitat within critical habitat areas. 

• Periodic watering for short-term stabilization of disturbed surface area. 

• Prevent track-out onto paved surfaces and clean up any tracked materials immediately. 

• Stabilize graded site surfaces upon completion of grading when subsequent development is 

delayed or expected to be delayed more than 30 days, except when such a delay is due to 

precipitation that dampens the disturbed surface sufficiently to eliminate visible fugitive 

dust emissions. 

Prevent Erosion and Sedimentation 

Applicant shall employ permanent stabilization measures upon completion of construction 

along washes and in other areas of potential erosion. 

Minimize Impacts on Water Availability 

Water will be obtained from existing commercially available water sources during construction. 

No new groundwater wells or surface water impoundments will be developed without federal, 

state, and local permits as appropriate and legally required. 

Drainage Systems Design 

Existing stormwater systems will be designed or redesigned to accommodate runoff from 

impervious surfaces. Drainage facilities shall detain flows and shall not contribute to additional 

flows in rivers, streams, and washes. 

Avoid Providing Nesting Sites for Opportunist Predators 

All new utility lines and ancillary structures associated with the Project shall be designed in a 

manner that will reduce the likelihood of nesting, especially by common ravens. 

Incorporate Site-Specific Permanent Water Quality Treatment Devices 

Permanent water quality treatment devices that comply with state and local requirements, as 

applicable, will be installed to meet water quality objectives. 

Construction Noise and Vibration Control Measures 

The contractor shall employ noise control measures to reduce noise from construction 

including: 

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• Use equipment with enclosed engines and/or high-performance mufflers. 

• Locate stationary construction equipment as far as possible from noise-sensitive sites. 

• Construct noise barriers, such as temporary walls or piles of excavated material, between 

noisy activities and noise-sensitive receivers. 

• Route truck traffic along roadways that will cause the least disturbance to species. 

• Avoid impact pile driving wherever possible. Use drilled piles or sonic/vibratory pile driver 

wherever possible. If impact pile drivers must be used near noise-sensitive receptors, 

implement a slow start and limit activity to daylight hours. 

Implement Litter-Control Program 

The contractor shall implement a litter-control program during construction to avoid subsidizing 

(feeding) generalized scavengers, such as common ravens. The program will include: 

• Use of covered, common-raven-proof trash receptacles 

• Daily removal of trash from the trash receptacles 

• Daily site inspections 

• Proper disposal of trash in a designated solid waste disposal facility 

Precautions will also be taken to prevent trash from blowing out of construction vehicles. 

Implement Housekeeping to Deter Opportunist Predators 

To mitigate subsidized predation, operational standards will be planned and implemented to 

maintain railway and stations free of food and habitat elements that facilitate opportunist 

predators. 

Prohibited Items and Feeding of Wildlife 

Feeding of wildlife shall not be allowed. No pets or firearms will be allowed in the construction 

area. 

Maintain Existing Wildlife Crossings 

New culverts, bridges, and viaducts shall align with any existing I-15 structures to maintain a 

continuous wildlife crossing corridor. Where the alignment of new culvert, bridges, or viaduct 

would deviate from alignment with existing I-15 structures, the Applicant shall design and 

install appropriately sized crossing structures at appropriate intervals to allow for terrestrial 

wildlife to pass under the proposed alignment. 

Avian Species Preconstruction Surveys 

Prior to the start of vegetation or ground disturbing activities, field surveys for the presence of 

suitable habitat for nesting avian species (least Bell’s vireo, western yellow-billed cuckoo, and 

southwestern willow flycatcher) at locations of potentially suitable habitat within the 

temporary and permanent limits of disturbance (LOD) shall be conducted by biologists that 

meet USFWS’s minimum qualifications (Halterman et al. 2015; Sogge et al. 2010; USFWS 1997, 

2019 and 2001). Surveys for the presence of suitable habitat for coastal scrub nesting avian 

species (coastal California gnatcatcher) at locations of potentially suitable habitat shall be 

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conducted prior to the start of construction by biologists that meet USFWS’s minimum 

qualifications (USFWS 2019). Coordination with USFWS prior to implementation and on the 

results of any survey is required. 

Stockpile Native Topsoil for Reuse in Restoration 

The contractor shall stockpile and protect removed native topsoil and shall use the stockpiled 

topsoil in restoration and landscaped areas. Areas from where topsoil is recovered shall be free 

from invasive plant species. 

Irrigation 

In consultation with the Caltrans District Landscape Architect, permanent or temporary 

irrigation systems to supply water to replacement landscape plantings shall be developed and 

implemented. 

Minimize Negative Effects of Nighttime Operational Lighting 

Nighttime lighting at passenger stations and along the rail alignment shall incorporate 

minimized light intensity, duration, and distribution and will utilize wildlife- and insect-sensitive 

spectrum lighting to reduce the negative effects of artificial nighttime lighting to sensitive 

species. Passenger stations shall incorporate light and glare screening measures—for example, 

use downward-cast lighting—and shall use motion sensor lighting, where appropriate. 

Remove Track-Killed Animals 

The Applicant will promptly remove all track-killed animals along the operating rail line to 

reduce adverse effects associated with food subsidies to opportunist predators, such as 

common ravens. 

Remove Common Raven Nests 

The applicant shall annually monitor catenary and ancillary structures, power poles, auxiliary 

buildings, passenger stations, and parking areas to identify and remove common raven nests 

outside of the nesting season. Once raven nesting sites are identified, actions will be taken to 

block the site from raven reuse. In coordination with USFWS, adaptive management may be 

undertaken if the initial measures are unsuccessful to remove common raven nests. 

Operations of Passenger Stations 

To mitigate potential subsidized predation, the Applicant shall plan and implement operational 

standards for maintaining railway and passenger stations to not support opportunist predators. 

Stations and other operations areas shall always be free of food sources and will eliminate 

habitat support elements that facilitate opportunist predators. 

Invasive Plant Species Control During Operations 

Following the completion of construction activities, the Applicant shall develop an Invasive 

Plant Species Monitoring and Control Plan for review and approval by USFWS. Invasive plant 

species in the temporary disturbed areas and operational areas shall be monitored: 

• Monthly from January through June for two growing seasons following construction 

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Control may consist of manual or herbicide control methods. Note that herbicide use in riparian 

areas and waters of the state is regulated. Herbicide use may be curtailed or avoided in desert 

tortoise habitat areas. 

7.4.2. Arroyo (Southwestern) Toad 

AT-1. Arroyo Toad Preconstruction Surveys 

Surveys for the presence of suitable habitat for arroyo toad will be conducted by qualified 

biologists prior to the start of construction. Coordination with USFWS prior to implementation 

of any survey is required. 

Presence/absence surveys will be conducted at all locations identified to have suitable habitat 

prior to the start of construction. Depending upon survey findings, additional protective 

measures during construction may be required. 

Survey procedures will be consistent with survey protocols for arroyo toad (USFWS 1999a). To 

be reasonably confident that arroyo toads are not present at a site, at least six (6) surveys must 

be conducted with at least 7 days between surveys. Surveys will be conducted during the 

breeding season, which generally occurs from March 15 through July 1. Extreme weather 

conditions can cause variations in the breeding season; these conditions should be fully 

considered when developing a schedule of surveys. 

7.4.3. San Bernardino Merriam’s Kangaroo Rat

SBKR-1. San Bernardino Kangaroo Rat Restricted Work Areas 

In collaboration with USFWS and prior to the start of any ground disturbance, the biologist shall 

identify areas within the construction temporary and permanent limits of disturbance (LOD) 

that may support San Bernardino Merriam’s kangaroo rat. These areas shall be called “SBKR 

restricted work areas.” They would most likely be located along the Project alignment between 

the vicinity of Hall Ranch Road to the vicinity of Summit Avenue and include Cajon Wash. Lytle 

Creek, and terraces adjacent to these features. Areas of existing infrastructure and areas lying 

between I-15 highway lanes (median) in these vicinities would not be included in restricted 

work areas. Coordination with a USFWS shall occur to identify and refine the geographical 

boundary of the SBKR restricted work areas. 

SBKR-2. San Bernardino Merriam’s Kangaroo Rat Preconstruction Surveys

The contractor or Applicant shall implement surveys for San Bernardino Merriam’s kangaroo rat 

prior to initiation of ground-disturbing activities in the SBKR restricted work areas. Coordination 

with USFWS shall occur prior to implementation of any surveys for San Bernardino Merriam’s 

kangaroo rat. Surveyors shall obtain ESA Section 10(a) permits, as necessary. Areas to be 

surveyed and results of surveys will be coordinated with USFWS. 

SBKR-3. Construction Monitoring and Reporting Requirements for SBKR Restricted Work 

Areas 

For the duration of construction work within the SBKR restricted work area, the biologist(s) 

shall: 

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• Review the previous week’s construction activities and the upcoming week’s construction 

activities to determine if there are areas that need additional inspection, fencing, or 

monitoring. 

• Inspect the San Bernardino Merriam’s kangaroo rat barrier fencing daily during active 

ground disturbance. 

• Inspect San Bernardino Merriam’s kangaroo rat barrier fencing weekly during any pause in 

construction of greater than 1 week. 

• Search the construction footprint for any kangaroo rat sign early in the morning and prior to 

any ground-disturbing activities. 

• Contact USFWS immediately if kangaroo rat sign is detected inside the barrier fencing. 

• Provide a weekly written report of construction monitoring activities and findings to USFWS 

within 4 business days following the end of each week during ground-disturbing 

construction within the SBKR restricted work area. 

SBKR-5. Install and Maintain San Bernardino Merriam’s Kangaroo Rat Barrier Fencing 

Within any portion of the SBKR restricted work area and prior to initiating ground-disturbing 

activities, San Bernardino Merriam’s kangaroo rat barrier fencing shall be installed between the 

construction activities and the surrounding area. 

• San Bernardino Merriam’s kangaroo rat barrier fencing will be constructed. San Bernardino 

Merriam’s kangaroo rats can be excluded with fencing suitable for effective small mammal 

exclusion that uses anti-climb technology, 30 to 36 inches high above ground with the 

bottom buried at least 12 inches deep and with a 6-inch apron lying at 12 inches deep at a 

right angle. 

• No gaps greater than 0.5 inch will be allowed. 

• The biologist or the biologist’s representative will be present when the fence is installed to

ensure that no burrows or burrow entrances are covered by the apron of the barrier fence. 

• The construction monitor will check the temporary barrier fencing at the close of each 

workday to ensure it is in place and properly maintained. 

• Fence gaps greater than 0.5 inch will be repaired within 24 hours of detection. 

SBKR-6. Preconstruction Trapping 

Prior to ground disturbance, the biologist(s) shall conduct preconstruction trapping inside 

exclusion fenced areas. Trapping will be conducted at each location until no San Bernardino 

Merriam’s kangaroo rats are trapped for two consecutive nights. Initial trapping is required to 

be performed on the evening of the first day on which the barrier fence installation is complete. 

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SBKR-7. Trapped San Bernardino Merriam’s Kangaroo Rat Housing and Release

The biologist(s) shall house and release all captured San Bernardino Merriam’s kangaroo rats as 

soon as possible following trapping. The captured San Bernardino Merriam’s kangaroo rats will 

be housed in suitable facilities until the released. The protocol for housing trapped San 

Bernardino Merriam’s kangaroo rats will follow holding/animal care requirements. Captured 

San Bernardino Merriam’s kangaroo rats will be translocated by soft-release into appropriate 

receiving habitat. 

7.4.4. Desert Tortoise 

DT-1. Desert Tortoise Potential, or Actual, Presence and Response 

Desert tortoise is not likely to occur within the construction area; thus, preconstruction surveys 

are not required at this time. If desert tortoise sign, burrows, or individuals are determined to 

be, or possibly be, present in areas of ground disturbance, then USFWS shall be notified 

immediately. 

In any situation where a desert tortoise places itself in danger (e.g., it enters a work area), 

immediate action will be undertaken protect the animal and the USFWS will be contacted for 

additional guidance. Work in the vicinity that could injure or kill the animal will immediately 

cease. The animal will be observed until it is moved with USFWS approval from harm’s way.

DT-2 Design and Install Suitable Culverts 

Where culverts are used, the Applicant shall design and install desert tortoise-suitable culverts. 

Box culverts must be at least 3 feet on a side, and pipe culverts must be at least 3 feet in 

diameter. Box culverts are recommended over pipe culverts because desert tortoises are less 

likely to use box culverts as burrows. If a new culvert is to be tied to an existing culvert under 

I-15, the Applicant, with approval from USFWS, may forego these specifications if they are 

incompatible with the existing culverts. 

DT-3. Notification of Desert Tortoise Injury or Death 

The contactor and or Applicant shall notify the Project’s point of contact at the Carlsbad Office 

of USFWS by telephone or electronic mail within 3 days of desert tortoise injury or death. The 

notification must include the date, time, and location of the carcass; a photograph; cause of 

death, if known; and any other pertinent information. The circumstances surrounding the 

incident will be reviewed with USFWS to determine whether additional protective measures are 

required for the Project. Project activities may continue during the review, provided that the 

proposed protective measures have been, and continue to be, fully implemented. 

DT-6. Refer to USFWS Regarding Desert Tortoise 

Construction crew members will refer all issues regarding the desert tortoise to the USFW. 

DT-7. Provide Rock-Slope Protections 

Placement and construction of rock-slope protections shall require the interstitial spaces within 

rock-slope protection to be filled with substrate to prevent trapping of desert tortoises. 

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7.4.5. ESA-Listed Plant Species Protection 

P-1. ESA-listed Plants Preconstruction Surveys 

Qualified botanists will conduct preconstruction surveys within suitable habitat for ESA-listed 

plant species prior to any vegetation or ground disturbing activities. 

P-2. Protect ESA-listed Plant Populations 

Prior to initiating ground-disturbing or vegetation disturbing activities, temporary construction 

fencing shall be placed around all ESA-listed plant species that occur within the temporary 

construction areas. When ESA-listed plants are observed within temporary construction areas, 

avoidance and minimization measures shall be applied. Exclusionary areas shall be signed for 

avoidance by construction equipment and personnel. Depending on the proximity of the 

ESA-listed plant populations to the construction work area, the plant populations shall be 

monitored during and following construction to avoid adverse effects. 

P-3. Avoid Known Special-Status Plant Populations 

To the extent possible, the Project shall completely avoid areas with ESA-listed plant 

populations by designing viaduct piers outside such areas. 

7.4.6. Monarch Butterfly 

MB-1. Provide and Support Pollinator and Nectary Sources 

Pollinator plants and milkweed species supporting monarch butterflies must be included in 

plans for restoration and landscape areas. 

7.4.7. Nesting Migratory Birds 

MBTA-1. Coordinate Construction Timing to protect Migratory Birds 

In areas of suitable nesting habitats for any migratory bird species at the Mojave River, Lytle 

Creek, Cajon Wash, Cajon Canyon, and Cajon Summit, initial ground and vegetation disturbance 

during construction would be scheduled to avoid migratory bird nesting, which range from 

March 1 to approximately July 15, to avoid take under the MBTA. Specific locations of suitable 

habitat and the timing for species likely to be present at each location shall be determined by 

the biologist and coordinated with construction activities prior to any vegetation or ground 

disturbing construction. 

7.5. Proposed Compensation for Unavoidable Impacts 

Compensation would be provided by the Project for any minimized, unavoidable impacts on 

protected species, critical habitat, migratory birds, or eagles. 

Compensation for unavoidable impacts could be provided as onsite restoration/creation, offsite 

restoration, or acquisition of mitigation credits, acquisition of conservation land, or a 

combination of methods. 

Caltrans completed an advance mitigation study in 2020 for their Mojave Desert operating area 

to identify opportunities to use conservation banks, mitigation banks, HCPs, natural community 

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conservation plans, in-lieu fee programs, or mitigation credit agreements to compensate for 

project impacts (Caltrans 2020). While the study evaluated only Caltrans-led projects, the study 

analyzed Caltrans projects on the I-15 corridor. Therefore, the study is geographically relevant 

to habitats and species for the Project and provides information on potential mitigation 

possibly available to the Project. 

Mitigation goals for projects in the Caltrans right-of-way include (Caltrans 2020): 

• Conserve and expand existing desert tortoise habitat (WILD-1) 

• Preserve, enhance, and increase connectivity between blocks of desert tortoise habitat 

(WILD-2) 

• Support resiliency of the landscape to climate change (WILD-3) 

• Decrease desert tortoise mortality (WILD-4) 

• Provide multi-species benefits (WILD-5) 

Caltrans’ Advance Mitigation Study (2020) showed that, while there were limited mitigation 

opportunities, several new opportunities were in development in 2020. The Town of Apple 

Valley multispecies HCP was in process, and it, along with the existing West Mojave HCP, may 

apply to transportation-related activities to meet mitigation obligations. 

In addition, the Mojave Desert Tortoise Umbrella Conservation Bank, Cajon Creek Habitat 

Conservation Management Area, and the Lytle Creek Conservation Bank (in process) could 

potentially provide mitigation credits to the Project. 

Two resource conservation investment strategies are under development with service areas for 

mitigation credit agreements possibly overlapping the Project. In particular, the San Bernardino 

County Regional Conservation Investment Strategy (SBC et al. 2018) provides for compensation 

to 13 general vegetation communities, along with focal species, and the needed landscape and 

habitat features that supports them. Once Regional Conservation Investment Strategies are 

approved by CDFW, any entity may develop projects that result in advance mitigation credits 

that may be transferred to compensate other projects. 

The City of Fontana has developed the North Fontana Conservation Plan (Fontana 2016) to 

assist in protection of San Bernardino Merriam’s kangaroo rat, coastal California gnatcatcher, 

slender-horned spineflower, and Santa Ana River woolly-star for areas that are to be 

developed. The conservation plan has proposed a 5:1 mitigation ratio for compensation of 

impacts on areas occupied by these ESA-listed species. This provides an indication of a potential 

mitigation ratio that could be used for compensation for the Project. 

The Cajon Creek Conservation Bank (Vulcan 2017) protects more than 1,300 acres of 

Riversidean Alluvial Fan Sage Scrub located in Cajon Wash and Lytle Creek and makes mitigation 

credits available for purchase to compensate for unavoidable impacts. Mitigation credits may 

be available to the Project if a need is identified. 

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8. Consultation with USFWS 

Based on analysis, adverse effects are likely to ESA-listed San Bernardino Merriam’s kangaroo 

rat, arroyo toad, slender-horned spineflower, and Santa Ana River woolly-star. The Project is 

also likely to adversely affect biological and physical factors in designated critical habitats for 

southwestern willow flycatcher, arroyo toad, and San Bernardino Merriam’s kangaroo rat. 

At the time of this writing, FRA is conducting formal consultation with USFWS under Section 7 

of the ESA. FRA will also coordinate with USFWS to identify acceptable strategies under the 

MBTA and the BGEPA for the Project. 

During formal consultation, USFWS will review the effects determination presented in the 

Project’s Biological Assessment, determine if clarification or additional information is needed, 

and determine if USFWS agrees with the effects determinations for each species and critical 

habitats. USFWS will develop a Biological Opinion If appropriate, USFWS will prepare an 

Incidental Take Statement, which would identify species, numbers of individuals, and timing of 

possible take by the Project USFWS will also identify conditions that would trigger re-opening of 

the consultation—for example, if changes in project construction methods, such as the addition 

of blasting, or changes in species listings from candidate to proposed or listed were to occur. 

. 

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9. References 

Abella, R.K., V.C. Bleich, R.A. Botta, B.J. Gonzales, T.R. Stephenson, S.G. Torres, and 

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Appendix A 

Temporary and Permanent Wildlife 

Habitat Impacts Maps 

BIOLOGICAL RESOURCES TECHNICAL REPORT, JULY 2022 

BRIGHTLINE WEST CAJON PASS HIGH-SPEED RAIL PROJECT 

BIOLOGICAL RESOURCES TECHNICAL REPORT, JULY 2022