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Attachment H: Biological Resources Technical Report

1.0 Introduction

The DesertXpress Enterprises, LLC XpressWest High-Speed Train Project (Project) entails construction 

and operation of a high-speed passenger train system between Apple Valley, and Las Vegas, Nevada. 

The Project was originally evaluated in the following documents (collectively referenced as the 

DesertXpress Environmental Impact Statement [EIS]):

• March 2009 Draft Environmental Impact Statement and 4(f) Evaluation for the proposed 

DesertXpress High-Speed Passenger Train (DesertXpress DEIS)

• April 2010 Supplemental Draft Environmental Impact Statement and 4(f) Evaluation for the proposed 

DesertXpress High-Speed Passenger Train (DesertXpress SEIS)

• March 2011 Final Environmental Impact Statement and 4(f) Evaluation for the proposed 

DesertXpress High-Speed Passenger Train Victorville, California to Las Vegas, Nevada (DesertXpress 

FEIS)

The Federal Railroad Administration (FRA) issued the Record of Decision DesertXpress High-Speed 

Passenger Train (DesertXpress ROD) in July 2011.

This technical report describes the potential changes to biological resource impacts with the Project 

modifications.

2.0 Regulatory Updates 

The regulatory environment for biological resources is described in detail in Section 3.14.1.1-3 of the 

DesertXpress DEIS and Section 3.14.1.2 of the DesertXpress FEIS. Land use designations and the 

regulatory status of each species evaluated in the DesertXpress EIS were verified during this analysis and 

any changes are included in the applicable section of this report. Below are changes to the regulatory 

environment since the issuance of the DesertXpress ROD. 

On September 14, 2016, the Bureau of Land Management (BLM) issued the ROD for the Desert 

Renewable Energy Conservation Plan (DRECP), which amended the California Desert Conservation Area 

(CDCA) Plan, the Bishop Resource Management Plan (RMP), and the Bakersfield RMP in the Mojave and 

Colorado/Sonoran Desert regions of southern California. The DRECP covers 22.5 million acres in seven 

California counties — Imperial, Inyo, Kern, Los Angeles, Riverside, San Bernardino, and San Diego — and 

includes 10.8 million acres of public lands administered by the BLM. The DRECP identifies priority areas 

for renewable energy development while setting aside areas for conservation and recreation. The plan 

also designated new Areas of Critical Environmental Concern (ACEC), as part of the BLM’s Land Use Plan 

Amendment for the DRECP. The modified Project is located within the DRECP Plan Area and intersects 

with five new ACECs (discussed in Section 4.2.6). 

On August 27, 2019, the U.S. Fish and Wildlife Service (USFWS) published three final rules that change 

the implementation of the Endangered Species Act (ESA) (16 United States Code [U.S.C.] § 1531 et. 

seq.). The final rules apply to Section 4 (listing and de-listing of endangered and threatened species; 

effective September 26, 2019) and Section 7 (consultation with Federal agencies; effective October 28, 

2019) of the ESA. 

Concurrently with the preparation of this Reevaluation, FRA submitted a letter to the USFWS on July 20, 

2020 seeking concurrence that the Project modifications do not require reinitiation of formal 
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consultation under Section 7. As described in the letter, FRA determined this approach was appropriate 

because impacts to species listed as threatened or endangered and critical habitat have been 

substantially reduced, and no new impacts would occur as a result of the Project modifications that 

were not previously addressed in the Biological Opinion issued for the Project. 

3.0 Methodology for Biological Field Surveys

3.1 VEGETATION MAPPING

For the DesertXpress DEIS, the Project footprint, including associated buffers to evaluated alternatives, 

was mapped during 2006-2010 field surveys. Most of the modified Project footprint is included in the 

area that was mapped as part of associated buffers. For areas of the modified Project footprint that 

were not included in the 2006-2020 field surveys, ICF biologists (Brad Haley and Phil Richards) 

conducted reconnaissance-level vegetation mapping of the modified Project footprint on September 24 

through 26, 2019, following the methods described in Section 3.14.2.3 of the DesertXpress DEIS. For 

consistency, vegetation was identified using the same classification scheme (Mojave Desert Ecosystem 

Program: Central Mojave Vegetation Database [USGS 2004]). Details of the weather conditions during 

the survey are shown in Table 3.1-1. 

Table 3.1-1 Weather Conditions during Modified Project Footprint Vegetation Mapping

Dates of 

Survey

Weather Conditions Approximate Temperatures 

During Survey

09/24/19 Clear with winds from 0–8 miles per hour (mph) 70–94 degrees Fahrenheit

09/25/19 15–50 percent cloud cover with winds from 0–8 mph 71–96 degrees Fahrenheit

09/26/19 60–100 percent cloud cover with winds from 0–15 mph; 

light rain 

82–94 degrees Fahrenheit

Between January 2020 and May 2020, further design modifications were incorporated into the Project 

footprint that required additional vegetation mapping. Since the modified footprint is immediately 

adjacent to areas previously evaluated during the 2019 field reconnaissance, updated vegetation 

mapping was completed through review of site photographs and associated desktop aerial imagery 

interpretation. 

As part of updating the vegetation mapping within the modified Project footprint, the California 

Department of Fish and Wildlife (CDFW) California Natural Diversity Database (CNDDB) list of sensitive 

vegetation community occurrences was refreshed and included in Attachment H1. 

3.2 SPECIAL-STATUS PLANTS

The appropriate survey window for special-status plants is between March and August. An evaluation 

was conducted where the modified Project footprint could provide suitable habitat for special-status 

plants; however, focused or protocol-level surveys for special-status plants were not conducted within 

the modified Project footprint. Based on the modified Project footprint, a query of the CNDDB 

(Attachment H2), California Native Plant Society Inventory of Rare and Endangered Plants (CNPS; 

Attachment H3), and USFWS Information for Planning and Consultation (IPAC; Attachment H4) was 

conducted for a list of special-status plant occurrences within the Project footprint and vicinity.
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3.3 SPECIAL-STATUS WILDLIFE

An evaluation was conducted where the modified Project footprint could provide suitable habitat for 

special-status wildlife; however, focused or protocol-level surveys for special-status wildlife were not 

conducted within the modified Project footprint. Based on the modified Project footprint, a query of the 

CNDDB (Attachment H5) and the USFWS IPAC (Attachment H4) was conducted for a list of federally

designated critical habitats and federally listed wildlife species within the Project footprint and vicinity.

Several additional special-status wildlife species and resources were evaluated for suitable habitat 

within the modified Project footprint but did not have focused or protocol-level surveys conducted. 

These include the following: burrowing owl, Mojave fringe-toed lizard, Clark County Habitat 

Conservation Plan-covered reptile species, banded Gila monster, roosting bats, American badger, desert 

bighorn sheep, nesting raptors, migratory birds, and wildlife movement corridors.

DESERT TORTOISE (THREATENED)

The Mojave population of the desert tortoise is Federally and California state-listed as a threatened 

species. In Nevada, desert tortoises are classified as a state protected and threatened species. This 

species is a covered species under the West Mojave Plan, which encompasses approximately 9.4 million 

acres of public land managed by the BLM. 

Based on USFWS and CDFW consultation from 2007 to 2011, no desert tortoise surveys were required 

within the Interstate (I)-15 freeway right-of-way (ROW). However, the Preferred Alternative included 29 

drainage crossings under the I-15 freeway that were surveyed for desert tortoise in 2007. The results of 

the survey were positive for desert tortoise signs and were included in the BA. In Nevada, it was 

determined that all areas outside the existing I-15 freeway ROW and outside the urbanized 

development in Primm, Jean, and Las Vegas Metropolitan area were occupied desert tortoise habitat. 

Tortoise surveys were not required in Nevada as part of the DesertXpress EIS and ESA Section 7 process. 

While no focused surveys were conducted as part of the habitat assessment, the vegetation mapping 

(described above) was conducted by biologists that are experienced in identifying desert tortoise signs 

and habitat. Focused surveys were not completed because of the following considerations: the existing 

BO calculated take and prescribed mitigation requirements, suitable habitat will be considered 

occupied, and impacts on suitable habitat would be significantly reduced relative to the footprint 

evaluated in the DesertXpress EIS. 

Meandering survey transects were walked by each biologist throughout the Dale Evans Station and 

Operations Maintenance and Storage Facility (OMSF), the Warm Springs Station, Frias Substation, and 

temporary construction areas in search of desert tortoise and their signs. These surveys were not 

focused or protocol-level. For areas that were not subject to meandering transects, habitat was 

evaluated.

SOUTHWESTERN WILLOW FLYCATCHER (ENDANGERED), LEAST BELL’S 

VIREO (ENDANGERED), AND WESTERN YELLOW-BILLED CUCKOO (THREATENED)

The southwestern willow flycatcher and least Bell’s vireo are Federally and California state-listed as 

endangered species. The western yellow-billed cuckoo is Federally listed as threatened and California 

state-listed as an endangered species. Based on the 2007 habitat assessment for southwestern willow 

flycatcher and least Bell’s vireo, the only portion of the Preferred Alternative that provided suitable 

habitat was Segment 1 over the Mojave River. USFWS protocol surveys were conducted for 
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southwestern willow flycatcher and least Bell’s vireo in the 2011 Project study area. The vegetation 

mapping described above was conducted by biologists experienced in identifying habitats for these 

species. Survey results were negative for both species. Suitable habitat for the western yellow-billed 

cuckoo was not identified in the 2011 Project study area. The Project component (Southern California 

Edison Utility Corridor in Victorville) that was proposed to cross the Mojave River is no longer a part of 

the modified Project. 

MOHAVE GROUND SQUIRREL (THREATENED)

This species is a state-listed threatened species and a BLM Sensitive species. This species is a covered 

species under the West Mojave Plan. Because of its BLM status, the habitat for this species was 

evaluated within the modified Project footprint by a qualified biologist (described above) during the 

habitat assessment using the methods described in Section 3.14.2.1 of the 2011 DesertXpress FEIS.

4.0 Effects Analysis for Biological Resources 

For this Reevaluation, the methodology described in Section 3.14.2.2 of the DesertXpress DEIS and 

Section 3.14.2 of the DesertXpress SEIS were used to evaluate impacts of the modified Project on 

biological resources. Similarly, the thresholds for determining impacts on vegetation and wildlife from 

Section 3.14.4.2 of the DesertXpress DEIS were used to evaluate effects from the modified Project 

footprint. The biological study area for the modified Project was reduced in size compared to the 2011 

study area, because the modified Project footprint is primarily located within the existing I-15 freeway

ROW. Based on the field survey and desktop analysis, areas of the modified Project footprint that were 

not previously evaluated were determined to contain biological resources of similar type, quality, and 

quantity, relative to the areas evaluated in the DesertXpress EIS. The following sections compare the 

previously evaluated biological resource impacts to those associated with the modified Project. 

4.1 VEGETATION MAPPING

The field survey of the modified Project footprint added a “Disturbed” classification to Creosote Bush 

Shrubland and Saltbush Complex communities throughout Segment 1 through Segment 6 within the I-15 

freeway corridor. The characteristic features described in Table 3.14-1 of the DesertXpress DEIS and 

Table 2 of the Special-Status Plant Survey Report for Segment 4C (ICF 2010) for all vegetation types were 

reviewed and found to be consistent with the vegetation types mapped within the modified Project

footprint. Table 4.1-1 shows the overall impacts (permanent and temporary impacts combined) on 

vegetation communities within the modified Project footprint. Table 4.1-2 and Table 4.1-3 separate the 

permanent and temporary impacts associated with the modified Project footprint. Table 4.2-4 shows 

total vegetation impacts, by impact type, for the original and modified Project footprints. 

Table 4.1-1 Modified Project Footprint Overall Vegetation Impacts (acres)

Vegetation Type Segment 1 Segment 2 Segment 3 Segment 4 Segment 5 Segment 6 Total**

Barren/Developed 246.9 294.2 582.1 242.6 189.6 211.6 1,766.8 

Blackbrush Shrubland - - 19.9 - - - 19.9 

Creosote Bush 

Shrubland

382.7 24.5 44.3 303.7 405.9 128.9 1,283.9 

Disturbed Creosote 

Bush Shrubland

2.1 27.9 185.1 2.1 18.3 11.5 246.9 
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Vegetation Type Segment 1 Segment 2 Segment 3 Segment 4 Segment 5 Segment 6 Total**

Desert Wash Scrub - 1.0 7.5 0.2 - 5.7 14.4 

Joshua Tree Wooded 

Shrubland*

- - 6.6 - - - 6.6 

Mojave Mixed Woody 

Scrub

- - 21.6 23.7 - 0.3 45.6 

Ruderal 5.4 - 0.5 - 13.2 14.4 32.7 

Saltbush Complex - 5.4 16.3 2.9 - - 24.7 

Disturbed Saltbush 

Complex

3.6 26.0 136.5 - - 15.7 181.7 

Sparse Vegetation - 3.1 1.2 - - - 4.3 

Total per Segment** 640.7 382.1 1,021.5 575.2 626.9 388.0 3,634.4

*Sensitive Vegetation Community

**Totals generated prior to rounding and therefore may not add precisely.

Table 4.1-2 Modified Project Footprint Permanent Vegetation Impacts (acres)

Vegetation Type Segment 1 Segment 2 Segment 3 Segment 4 Segment 5 Segment 6 Total**

Barren/Developed 232.8 215.4 458.6 121.6 41.2 66.4 1,136.0

Blackbrush Shrubland - - 7.1 - - - 7.1 

Creosote Bush 

Shrubland

382.6 12.0 33.5 74.3 169.3 91.4 763.1

Disturbed Creosote 

Bush Shrubland

2.1 12.5 155.5 0.9 - 4.5 175.4

Desert Wash Scrub - 0.9 5.4 0.2 - 5.7 12.1

Joshua Tree Wooded 

Shrubland*

- - 4.9 - - - 4.9

Mojave Mixed Woody 

Scrub

- - 15.4 5.3 - 0.3 21.0

Ruderal 5.4 - 9.7 12.3 27.4

Saltbush Complex - 3.0 7.1 - - - 10.0

Disturbed Saltbush 

Complex

3.3 6.0 121.8 - - 10.6 141.7

Sparse Vegetation - 0.2 - - - - 0.2

Total per Segment** 626.2 250.0 809.1 202.3 220.1 191.1 2,299.2

* Sensitive Vegetation Community

**Totals generated prior to rounding and therefore may not add precisely.
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Table 4.1-3 Modified Project Footprint Temporary Vegetation Impacts (acres)

Vegetation Type Segment 1 Segment 2 Segment 3 Segment 4 Segment 5 Segment 6 Total**

Barren/Developed 14.1 78.8 123.6 121.0 148.4 145.2 631.1

Blackbrush Shrubland - - 12.9 - - - 12.9

Creosote Bush 

Shrubland

0.1 12.4 10.8 229.4 236.6 37.6 525.5

Disturbed Creosote 

Bush Shrubland

- 15.4 29.6 1.2 18.3 6.9 71.5

Desert Wash Scrub - 0.2 2.1 - - - 2.3

Joshua Tree Wooded 

Shrubland*

- - 1.7 - - - 1.7

Mojave Mixed Woody 

Scrub

- - 6.2 18.4 - - 24.5

Ruderal - - 0.5 - 3.5 2.1 6.0

Saltbush Complex - 2.5 9.2 2.9 - - 14.6

Disturbed Saltbush 

Complex

0.3 19.9 14.7 - - 5.1 40.0

Sparse Vegetation - 2.8 1.2 - - - 4.0

Total per Segment** 

14.5 132.0 212.5 373.0 406.8 196.9 1,335.7

* Sensitive Vegetation Community

**Totals generated prior to rounding and therefore may not add precisely.

4.2 ENVIRONMENTAL CONSEQUENCES

INTRODUCTION OR SPREAD OF INVASIVE, NON-NATIVE WEED SPECIES INTO 

NATURAL VEGETATION COMMUNITIES

The effects related to the introduction and spread of invasive, non-native weed species, as described in 

Section 3.14.2.3 of the DesertXpress DEIS, still apply to the modified Project footprint. The 

implementation of Mitigation Measure BIO-4 (avoid dispersal) from the DesertXpress EIS would be 

implemented to reduce or mitigate adverse effects from noxious weeds, and the Project modifications 

would not result in substantial changes in the evaluation of invasive, non-native weed species impacts of 

the DesertXpress EIS.

LOSS OF OR DAMAGE TO NATIVE VEGETATION COMMUNITIES

The effects related to the loss of or damage to native vegetation communities, as described in Section 

3.14.2.3 of the DesertXpress DEIS, still apply to the modified Project footprint. Acreages of native 

vegetation communities that would be permanently or temporarily affected by the alignments, stations, 

and operations and maintenance facilities are presented in Table 4.2-4. The modified Project would 

result in substantially reduced acreages of permanent and temporary impacts on these vegetation 

communities relative to the DesertXpress EIS. Based on the habitat assessment, the modified Project

footprint would permanently convert approximately 1,135 acres and temporarily affect approximately
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695 acres of native vegetation communities, whereas the DesertXpress EIS estimated that the Preferred 

Alternative would permanently convert approximately 1,500 acres and temporarily affect 4,500 acres of 

native vegetation communities. In addition, most of the modified Project impacts now occur within the 

I-15 freeway ROW, which contains degraded quality native vegetation communities. Mitigation 

Measures BIO-5 (confine equipment), BIO-6 (revegetation), BIO-7 (retain topsoil), BIO-8 (restore 

topography), BIO-9 (erosion control), BIO-18 (Nevada compensatory mitigation), and BIO-18 (California 

compensatory mitigation) from the DesertXpress EIS (restated below) would be implemented to avoid, 

minimize or mitigate adverse effects from loss of or damage to native vegetation communities. Thus, 

the Project modifications would not result in substantial changes in the evaluation of native vegetation 

community impacts of the DesertXpress EIS.

Table 4.2-4 Comparison of Native Vegetation Community Impacts (acres)

Biological Resources

DesertXpress EIS (2011)

Modified Project (2020) Preferred 

Alternative Alternative A Alternative B Option C

Native Vegetation Communities1

-- Permanent Impact

1,432.3 to 

1,556.62

611.9 to 

747.13

1,473.6 to 

1,604.64

40.25 

38.05 1,135.3

Native Vegetation Communities -

- Temporary Impact 4,584.8 2,108.6 4,558.4 232.46 694.6

1 Native Vegetation Communities include: Blackbrush Shrubland, Creosote Bush Shrubland, Disturbed Creosote Bush Shrubland, 

Desert Wash Scrub, Joshua Tree Wooded Shrubland, Mojave Mixed Woody Scrub, Saltbush Complex, and Disturbed Saltbush 

Complex.

2 2011 Preferred Alternative total ranges from 1,432.3 acres with Victorville Station 1 and OMSF 1 to 1,566.6 acres with Victorville 

Station 2 and OMSF 2.

3 Alternative A totals range from 611.9 acres (Victorville Station 1 and OMSF 1) with the Wigwam Avenue Maintenance Storage 

Facility (MSF) to 747.1 acres (Victorville Station 2 and OMSF 2) with the Sloan Road MSF.

4 Alternative B totals range from 1,473.6 acres (Victorville Station 1 and OMSF 1) with the Wigwam Avenue MSF to 1,604.6 acres 

(Victorville Station 1 and OMSF 2) with the Sloan Road MSF.

5 Option C would add an additional 40.2 acres to the 2011 Preferred Alternative and Alternative B totals or 38 acres to the 

Alternative A total.

6 Option C would add an additional 232.4 acres to the Preferred Alternative, Alternative A, and Alternative B totals.

SENSITIVE VEGETATION COMMUNITIES

The effects related to the loss of sensitive vegetation communities, as described in Section 3.14.2.3 of 

the DesertXpress DEIS, still apply to the modified Project footprint. A previously evaluated sensitive 

plant community, Joshua Tree Wooded Shrubland, is present within Segment 3 of the modified Project

footprint. However, as outlined in Table 4.2-5 the acreage of permanent and temporary impacts on this 

sensitive vegetation community has been reduced substantially relative to the DesertXpress EIS analysis 

because the modified Project footprint is now primarily located within the I-15 freeway ROW. The 

DesertXpress EIS estimated that the Preferred Alternative would permanently convert approximately 84 

acres and temporarily affect 194 acres of Joshua Tree Wooded Shrubland. Based on the habitat 

assessment, the modified Project footprint would permanently convert approximately 4.9 acres and 

temporarily affect 1.7 acres of Joshua Tree Wooded Shrubland.

The DesertXpress EIS estimated that the Preferred Alternative would permanently convert 

approximately 2 acres and temporarily affect 13 acres of Mesquite Shrubland. The modified Project 

footprint is no longer anticipated to affect Mesquite Shrubland.
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Mitigation Measures BIO-5 (confine equipment), BIO-6 (revegetation), BIO-7 (retain topsoil), BIO-8 

(restore topography), BIO-9 (erosion control), BIO-10 (tree removal permit), BIO-11 (compensatory 

mitigation), and BIO-13 (pre-construction surveys) from the DesertXpress EIS (restated below) would be 

implemented to reduce or mitigate adverse effects from loss of sensitive vegetation communities. Thus, 

the Project modifications would not result in substantial changes in the evaluation of sensitive 

vegetation community impacts of the DesertXpress EIS.

Table 4.2-5 Comparison of Sensitive Vegetation Community Impacts (acres)

Biological Resources

DesertXpress EIS (2011)

Modified 

Project (2020)

Preferred 

Alternative

Alternative 

A 

Alternative 

B 

Option 

C 

Sensitive Plant Community –Permanent 

Impact (Joshua Tree Wooded Shrubland) 83.8 - 83.8 - 4.9 

Sensitive Plant Community –Permanent 

Impact (Mesquite Shrubland) 1.9 - 1.9 - 0.0

Sensitive Plant Community –Temporary 

Impact (Joshua Tree Wooded Shrubland) 194.4 - 194.7 - 1.7 

Sensitive Plant Community –Temporary 

Impact (Mesquite Shrubland) 13.4 4.6 13.4 - 0.0

POTENTIAL EFFECTS ON SPECIAL-STATUS PLANT POPULATIONS

The effects related to construction and operational activities on special-status plant populations, as

described in Section 3.14.2.3 of the DesertXpress DEIS, still apply to the modified Project footprint. Table 

3.14-2 through Table 3.14-7 in the DesertXpress DEIS, which provided a list of special-status plants with 

potential to occur in each Segment, were evaluated during this assessment. The modified Project

footprint minimizes adverse impacts on sensitive species identified in the DesertXpress EIS because 

most of the Project footprint is now within the I-15 freeway ROW, which provides little habitat for 

sensitive species. The biological resources are degraded within the modified Project footprint due to the 

proximity to existing maintained roadway infrastructure. Special-status plant surveys have not been 

conducted in California or reconducted in Nevada within the modified Project footprint. The 

implementation of Mitigation Measures BIO-5 (confine equipment), BIO-14 (avoid known populations),

and BIO-15 (mitigation) from the DesertXpress EIS would be implemented to reduce or mitigate adverse 

effects on sensitive plant populations, and the Project modifications would not result in substantial 

changes in the evaluation of special-status plant population impacts of the DesertXpress EIS. 

POTENTIAL EFFECTS ON SPECIAL-STATUS WILDLIFE

The modified Project footprint is now primarily located within the I-15 freeway ROW, which provides 

little to no habitat for special-status wildlife due to the proximity to existing maintained roadway 

infrastructure. As described below, the modified Project footprint would result in fewer acres of 

permanent and temporary impacts to wildlife habitat relative to the impacts evaluated in the 

DesertXpress EIS. Therefore, the Project modifications would not result in substantial changes in the 

evaluation of special-status wildlife impacts of the DesertXpress EIS.
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DESERT TORTOISE AND DESERT TORTOISE HABITAT

The effects related to construction and operational activities on desert tortoise individuals and desert 

tortoise habitat, as described in Section 3.14.2.3 of the DesertXpress DEIS, still apply to the modified 

Project footprint. Acreages of desert tortoise habitat (native vegetation communities) that would be 

permanently or temporarily affected by the alignment, stations, and operations and maintenance 

facilities are presented in Table 4.2-4 of this report. For comparison, the impacts evaluated in the 

DesertXpress EIS have been included in Table 4.2-4. The modified Project would result in fewer acres of 

permanent and temporary impacts, as compared to the impacts evaluated in the DesertXpress EIS. 

The greatest permanent impacts associated with the modified Project footprint are bound by the I-15 

freeway fencing. Tortoise exclusion fencing is present in California along the I-15 freeway from just 

north of the proposed Dale Evans Station and OMSF site in Segment 1 to just north of Yermo, then again 

near Baker through Mountain Pass. The fencing is also consistently present from Primm, Nevada, to Las 

Vegas, Nevada. In the 2011 BO for the Project, the USFWS determined that the loss of potential desert 

tortoise habitat close to the I-15 freeway was unlikely because the existing freeway facility severely 

fragments the habitat, the proposed habitat losses extended only a short distance from the I-15 

freeway, and habitat adjacent to freeways is often degraded for some distance from the edge of the 

road because of trash, routine maintenance, and predation by common ravens, raptors, coyotes, and 

feral animals. Additionally, because the habitat loss is distributed in such a linear manner along I-15

freeway, those areas would not be considered essential for the survival and recovery of the species or to 

provide any important habitat linkages. 

The Dale Evans Station and OMSF site (300 acres) and the Warm Springs Station (109 acres) would be 

located in areas that consist primarily of Creosote Bush Shrubland and make up nearly 50 percent of the 

permanent impacts on desert tortoise habitat from the modified Project. The Dale Evans Station and 

OMSF site is approximately the same size as the previously evaluated Victorville Station 3B and OMSF 2 

and is in approximately the same location, except on the east side of I-15 freeway rather than the west 

side. The Warm Springs Station in Las Vegas is within desert tortoise habitat; however, the area is not 

designated critical habitat and is surrounded by urban and commercial development, as well as the I-15 

freeway and other major roads, making it unlikely for tortoises to be present. 

The DesertXpress EIS estimated that the Preferred Alternative would permanently convert 

approximately 1,510 acres and temporarily affect 4,135 acres of desert tortoise habitat. Based on the 

habitat assessment, the modified Project footprint would permanently convert approximately 818 acres 

and temporarily affect approximately 582 acres of desert tortoise habitat. Implementation of Mitigation 

Measures BIO-1 (worker education program), BIO-2 (pre-construction surveys and fencing), BIO-3 

(monitoring), BIO-5 (confine equipment), BIO-15 (prepare translocation plan), BIO-16 (final monitoring 

plan), BIO-18 (Nevada compensatory mitigation), BIO-18 (California compensatory mitigation), and BIO19 (exclusion fencing and culverts) from the DesertXpress EIS, as well as additional minimization and 

compensatory mitigation measures included in the new BO (Section 3.2.8), would reduce or mitigate 

adverse effects on desert tortoise and desert tortoise habitat. 

MOHAVE GROUND SQUIRREL

Mohave ground squirrel is listed as threatened under the California Endangered Species Act. The effects 

related to construction and operational activities on Mohave ground squirrel, as described in Section 

3.14.2.3 of the DesertXpress DEIS, still apply to the modified Project footprint. Segment 1 and the 

southern portion of Segment 2 (Barstow/Yermo) provide suitable habitat for this species. The 
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DesertXpress EIS estimated that the Preferred Alternative would permanently convert approximately 

447 acres and temporarily affect 562 acres of Mohave ground squirrel habitat. Based on the habitat 

assessment, the modified Project footprint would permanently convert 398 acres and temporarily affect 

20 acres of Mohave ground squirrel habitat. Mitigation Measures BIO-1 (worker education program), 

BIO-2 (pre-construction surveys), BIO-3 (monitoring), BIO-5 (confine equipment), and BIO-20 (MGS 

compensatory mitigation) would be implemented to reduce or mitigate adverse effects on Mohave 

ground squirrel. 

MOJAVE FRINGE-TOED LIZARD

The Mojave fringe-toed lizard is a California species of special concern and is a BLM sensitive species. 

The species is known from within five miles of the Project area (CNDDB 2020). A habitat suitability 

model for the Mojave fringe-toed lizard was developed as part of the DRECP. The modified Project 

footprint occurs in areas that have been modeled as suitable habitat for this species. This habitat 

suitability model was developed in 2016 and was not available as a reference for the analysis of the 

Preferred Alternative in 2011. However, the effects related to construction and operational activities on 

Mojave fringe-toed lizard, as described in Section 3.14.2.3 of the DesertXpress DEIS, still apply to the 

modified Project footprint. The use of this habitat suitability model merely confirms that the habitat 

assessment completed in 2011 is consistent with the habitat assessment conducted for the modified 

Project. Segments 1, 2, and 3 provide suitable habitat for this species. The DesertXpress EIS estimated 

that the Preferred Alternative would permanently convert approximately four acres and temporarily 

affect eight acres of Mojave fringe-toed lizard habitat. Based on the DRECP suitable habitat model, 

nearly 85 acres of suitable habitat occurs within the modified Project footprint, with approximately 63 

acres of permanent impacts and 22 acres of temporary impacts. However, over 70 acres of impacts 

would occur within the I-15 freeway median, which does not appear to provide adequate habitat for the 

species due to its disturbed conditions. Therefore, based on the habitat assessment and species 

distribution model, the modified Project footprint would permanently convert four acres and 

temporarily affect 11 acres of Mojave fringe-toed lizard habitat. Mitigation Measures BIO-1 (worker 

education program), BIO-2 (pre-construction surveys and fencing), BIO-3 (monitoring), and BIO-5 

(confine equipment) would be implemented to reduce or mitigate adverse effects on Mojave fringetoed lizard.

NESTING RAPTORS AND MIGRATORY BIRDS

The modified Project would be located within suitable nesting habitat for special-status and migratory 

birds and raptors. Regulations under the Migratory Bird Treaty Act and the Bald and Golden Eagle 

Protection Act would apply to minimize the modified Project’s effects to nesting raptors and migratory 

birds. The DesertXpress DEIS Sections 3.14.1 includes a detailed description of the Migratory Bird Treaty 

Act and Bald and Golden Eagle Protection Act. 

Effects related to construction and operational activities on nesting raptors and migratory birds, as 

described in Section 3.14.2.3 of the DesertXpress DEIS, still apply to the modified Project footprint. The 

modified Project would result in fewer permanent and temporary impacts, in terms of acreage, on

vegetation communities that provide potential habitat for nesting raptors and migratory birds, 

compared to the impacts previously evaluated. The DesertXpress EIS estimated that the Preferred 

Alternative would permanently convert approximately 1,500 acres and temporarily affect 4,500 acres of 

native vegetation communities which provide suitable nesting bird and raptor habitat. Based on the 

habitat assessment, the modified Project footprint would permanently convert approximately 1,135
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acres and temporarily affect nearly 695 acres of native vegetation communities. Those totals include a 

reduction in impacts to Joshua Tree Wooded Shrubland (278 acres down to 6.6 acres) and Mesquite 

Shrubland (15 acres down to zero acres), which provide important nesting substrate for migratory birds 

and raptors. In addition, the majority of the I-15 freeway ROW does not provide suitable nesting habitat 

for migratory birds and raptors, with certain exceptions including existing electrical transmission line 

towers, Mountain Pass, and freeway overpasses. The modified Project footprint also no longer includes 

tunneling through the Clark Mountains. Mitigation Measures BIO-1 (worker education program), BIO-2 

(pre-construction surveys and fencing), BIO-3 (monitoring), and BIO-5 (confine equipment) would be 

implemented to reduce or mitigate adverse effects on nesting raptors and migratory birds.

BANDED GILA MONSTER

The banded Gila monster is a California species of special concern and is a BLM sensitive species. Banded 

Gila monster are known from within five miles of the modified Project (CNDDB 2020). In Nevada, the 

banded Gila monster is classified as state protected.

Effects related to construction and operational activities on banded Gila monster, as described in 

Section 3.14.2.3 of the DesertXpress DEIS, still apply to the modified Project footprint. Segment 4 

(Mountain Pass) provides suitable habitat for this species. The DesertXpress EIS did not provide an 

estimate on the quantity of impacts to banded Gila monster habitat. The Preferred Alternative passed 

through the Clark Mountains (north of Mountain Pass) which were the location of the closest records for 

the species in the area. The modified Project footprint no longer includes the Clark Mountains, and is 

now within the I-15 freeway median through the Mountain Pass area which provides lower quality 

habitat than the Clark Mountains. Mitigation Measures BIO-1 (worker education program), BIO-2 (preconstruction surveys and fencing), BIO-3 (monitoring), and BIO-5 (confine equipment) would be 

implemented to avoid direct mortality of banded Gila monster.

CLARK COUNTY HABITAT CONSERVATION PLAN-COVERED REPTILE SPECIES

The effects related to construction and operational activities on the Clark County HCP-covered reptile 

species, as described in Section 3.14.2.3 of the DesertXpress DEIS, still apply to the modified Project

footprint. These species include banded gecko, Great Basin collard lizard, desert iguana, large-spotted 

leopard lizard, desert tortoise, chuckwalla, western red-tailed skink, sidewinder, speckled rattlesnake, 

Mojave green rattlesnake, glossy snake, California king snake, western leaf-nosed snake, western longnosed snake, and Sonoran lyre snake. The modified Project would result in fewer permanent and 

temporary impacts, in terms of acreage, on suitable Clark County HCP-covered reptile species habitat, as 

compared to the impacts previously evaluated in the DesertXpress EIS. The DesertXpress EIS estimated 

that the Preferred Alternative would permanently convert approximately 248 acres and temporarily 

affect 821 acres of suitable habitat. Based on the habitat assessment, the modified Project footprint 

would permanently convert approximately 267 acres and temporarily affect nearly 274 acres of suitable 

habitat. Mitigation Measures BIO-1 (worker education program), BIO-2 (pre-construction surveys and 

fencing), BIO-3 (monitoring), and BIO-5 (confine equipment) would be implemented to avoid direct 

mortality of Clark County HCP-covered reptile species.

BURROWING OWL

Burrowing owls are a California species of special concern and a BLM sensitive species. Effects related to

construction and operational activities on burrowing owl, as described in Section 3.14.2.3 of the 

DesertXpress DEIS, still apply to the modified Project footprint. The modified Project would result in 
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fewer permanent and temporary impacts, in terms of acreage, on vegetation communities that provide 

potential habitat for burrowing owls, as compared to the impacts previously evaluated in the 

DesertXpress EIS. The DesertXpress EIS estimated that the Preferred Alternative would permanently 

convert approximately 1,510 acres and temporarily affect 4,135 acres of burrowing owl habitat. Based 

on the habitat assessment, the modified Project footprint would permanently convert 1,163 acres and 

temporarily affect 704 acres of burrowing owl habitat. The temporary and permanent impacts on

burrowing owl habitat are slightly larger as for the native vegetation communities listed in Table 4.2-4

because suitable owl habitat includes non-native vegetation communities as well. MMs BIO-1 (worker 

education program), BIO-2 (pre-construction surveys and fencing), BIO-3 (monitoring), BIO-5 (confine 

equipment), and BIO-21 (avoid or passively relocate owls) would be implemented to minimize or avoid 

potential loss or disturbance of burrowing owls. 

ROOSTING BATS

The effects related to construction and operational activities on roosting bats, as described in Section 

3.14.2.3 of the DesertXpress DEIS, still apply to the modified Project footprint, though in a greatly 

reduced capacity now that the modified Project alignment would run parallel to the I-15 freeway 

primarily within the I-15 freeway corridor. The DesertXpress EIS specifically mentioned caves and mines 

in the Clark Mountains as potential bat roosting and nursery sites, which the modified Project footprint 

no longer includes. Bridges throughout the I-15 freeway corridor along Segment 1 through Segment 6 

provide potential roosting and nursery sites for bats. Mitigation Measures BIO-1 (worker education 

program), BIO-2 (pre-construction surveys and fencing), BIO-3 (monitoring), and BIO-5 (confine 

equipment) would be implemented to minimize or avoid potential loss or disturbance of roosting bats.

AMERICAN BADGER

The American badger is a California species of special concern. Effects related to construction and 

operational activities on American badger, as described in Section 3.14.2.3 of the DesertXpress DEIS, still 

apply to the modified Project footprint, though in a greatly reduced capacity now that the modified 

Project alignment would run parallel to the I-15 freeway within the I-15 freeway corridor. The 

DesertXpress EIS estimated that the Preferred Alternative would permanently convert approximately 

1,510 acres and temporarily affect 4,135 acres of badger habitat. Based on the habitat assessment, the 

modified Project footprint would permanently convert approximately 1,135 acres and temporarily affect 

nearly 695 acres of badger habitat. Mitigation Measures BIO-1 (worker education program), BIO-2 (preconstruction surveys and fencing), BIO-3 (monitoring), BIO-5 (confine equipment), and BIO-19 (construct 

culverts) would be implemented to minimize or avoid potential loss or disturbance of American badger.

DESERT BIGHORN SHEEP

Desert bighorn sheep are a fully protected species under CDFW code and a BLM sensitive species. 

Effects related to construction and operational activities on desert bighorn sheep, as described in 

Section 3.14.2.3 of the DesertXpress DEIS, still apply to the modified Project footprint, though in a 

greatly reduced capacity now that the modified Project alignment would run in the median of the I-15 

freeway corridor. Segment 4 (Mountain Pass) is where the I-15 freeway median contains the Wheaton 

Springs Wash. The modified Project footprint would be directly adjacent to the northbound interior lane 

of the I-15 freeway. The rail alignment in the Mountain Pass area would no longer involve tunnels and 

would be elevated over the wash in the same locations as the I-15 freeway. Therefore, the previous 

effects related to tunnels causing direct mortalities and the rail creating a movement barrier to bighorn 

sheep have been substantially reduced or eliminated. Mitigation Measures BIO-1 (worker education 
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program), BIO-2 (pre-construction surveys and fencing), BIO-3 (monitoring), BIO-5 (confine equipment), 

and BIO-19 (wildlife crossings) would be implemented to minimize or avoid direct effects on desert 

bighorn sheep.

SOUTHWESTERN WILLOW FLYCATCHER, LEAST BELL’S VIREO, AND WESTERN YELLOW-BILLED 

CUCKOO

The Project modifications would not encounter suitable habitat for southern willow flycatcher, least 

Bell’s vireo, or western yellow-billed cuckoo. The modified Project footprint no longer includes the SCE 

Utility Corridor that was proposed to cross the Mojave River south of Victorville. Based on the modified 

Project footprint, the closest suitable habitat for these species are now over six miles south of the Dale 

Evans Station and OMSF site. As no suitable habitat occurs within the Project area, no impacts on

suitable habitat are anticipated to occur. Based on the 2011 BO, the Project would incorporate 

avoidance measures through the design and construction schedule approved by the USFWS in their 

acknowledgement of FRA’s no effect determination for these species. These avoidance measures, along 

with Mitigation Measure BIO-13 (pre-construction surveys) are no longer necessary for these species. 

WILDLIFE MOVEMENT

The effects related to construction and operational activities on wildlife movement, as described in 

Section 3.14.2.3 of the DesertXpress DEIS, still apply to the modified Project footprint, though in a 

greatly reduced capacity now that the modified Project would be within the I-15 freeway corridor, which 

is itself an existing barrier to wildlife. The Dale Evans Station and OMSF site and Warm Springs Station 

are unlikely to isolate individuals or fragment habitat because they are adjacent to the I-15 freeway 

corridor and, for Warm Springs, already surrounded by urban and industrial land uses. Habitat 

fragmentation or isolation as a result of the modified Project footprint is not anticipated. Existing 

culverts and wildlife crossing locations under the I-15 freeway corridor would remain in place. The 

implementation of Mitigation Measures BIO-3 (monitoring) and BIO-19 (exclusion fencing, culverts, and 

wildlife crossings) from the DesertXpress EIS, as well as minimization and mitigation measures outlined 

in the BO, would be implemented to reduce or mitigate adverse effects on wildlife movement.

POTENTIAL EFFECTS ON SPECIAL MANAGEMENT LANDS

The effects related to construction and operational activities on Special Management Lands, as 

described in Section 3.14.2.3 of the DesertXpress EIS, still apply to the modified Project footprint, 

though in a greatly reduced capacity now that the modified Project footprint would primarily be within 

the I-15 freeway corridor. The modified Project would affect two types of Special Management Lands: 

USFWS critical habitat and BLM ACECs. Table 4.2-6 and Table 4.2-7 show the permanent and temporary 

impacts from the DesertXpress EIS and the modified Project footprint on Special Management Lands. 

Although the modified Project footprint would intersect USFWS critical habitat and BLM ACECs, most of 

the areas where impacts would occur no longer provide the habitat or unique value for which the area 

was designated. Each of these Special Management Lands are bound by I-15 freeway on one side or are 

bisected by I-15 freeway. Most of the modified Project footprint is within the I-15 freeway ROW, which 

is relatively degraded and subject to trash, routine maintenance, and disturbances from vehicles leaving 

the freeway. 
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Table 4.2-6 Comparison of Permanent Impacts to Special Management Lands (acres)

 DesertXpress EIS (2011)

Modified 

Project (2020) Special Management Lands Preferred 

Alternative Alternative A Alternative B Option C

Desert Tortoise Critical Habitat 575.6 60.9 555.0 - 291.2

Superior-Cronese ACEC - - - - 3.8

Cronese Basin ACEC 3.6 - 3.6 - 1.9

Ivanpah ACEC - - - - 64.9

Northern Lucerne Wildlife 

Linkage ACEC - - - - 8.5

Shadow Valley ACEC - - - - 91.6

Soda Mountains Expansion 

ACEC - - - - 110.3

Halloran Basin ACEC - - - - -

NPS Mojave National Preserve 13.8 13.8 - - -

Total* 593.0 74.7 558.6 0 572.2 

*Totals generated prior to rounding and therefore may not add precisely.

Table 4.2-7 Comparison of Temporary Impacts to Special Management Lands (acres)

DesertXpress EIS (2011)

Modified Project 

(2020) Special Management Lands Preferred 

Alternative Alternative A Alternative B Option C

Desert Tortoise Critical Habitat 1,703.6 264.0 1,598.9 - 107.1 

Superior-Cronese ACEC - - - - 3.5 

Cronese Basin ACEC 16.6 - 16.6 - 0.4 

Ivanpah ACEC - - - - 194.9 

Northern Lucerne Wildlife 

Linkage ACEC - - - - - 

Shadow Valley ACEC - - - - 30.8 

Soda Mountains Expansion 

ACEC - - - - 21.6 

Halloran Basin ACEC 25.5 - 25.5 - - 

NPS Mojave National Preserve 59.9 59.9 - - - 

Total* 1,805.6 323.9 1,641.0 - 358.3 

*Totals generated prior to rounding and therefore may not add precisely.

CRITICAL HABITAT

Critical habitat is defined in Section 3(5)(A) of the ESA (16 U.S.C. § 1532(5)(A)) as “specific areas within 

the geographic area occupied by the species, at the time it is listed in accordance with the provisions of 
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Section 4 of this Act, on which are found those physical or biological features (I) essential to the 

conservation of the species and (II) which may require specific management considerations or 

protection; and specific areas outside the geographical area occupied by the species at the time it is 

listed in accordance with the provisions of Section 4 of this Act upon a determination by the Secretary 

[of the Interior] that such areas are essential for the conservation of the species.” The designation of 

critical habitat for a listed species helps focus conservation activities by identifying areas that contain 

essential habitat features regardless of whether they are currently occupied by the listed species.

Designated critical habitat for desert tortoise is present within the modified Project footprint; the 

impacts are described below. Based on modified Project construction and operation activities as well as 

the modified Project footprint occurring within the I-15 freeway median, the modified Project footprint 

is not expected to change the intended conversion purpose or inhibit the ability of the Primary 

Constituent’s Elements (PCE) to be functionally established within the critical habitat. The Project 

modifications would not result in substantial changes in the evaluation of critical habitat impacts of the 

DesertXpress EIS.

Desert Tortoise Critical Habitat

Impacts on the Superior-Cronese and Ivanpah Critical Habitat Units were previously evaluated in the 

DesertXpress EIS. Based on the modified Project footprint, impacts have been substantially reduced in 

terms of acreage and quality of habitat being affected. The DesertXpress EIS estimated that the 

Preferred Alternative would permanently convert approximately 576 acres and temporarily affect 1,704 

acres of desert tortoise critical habitat. The 2020 modified Project footprint would permanently convert 

approximately 291 acres and temporarily affect 107.1 acres of desert tortoise critical habitat (Table 4.2-

6 and Table 4.2-7). Permanent impacts on the Superior-Cronese Critical Habitat Unit include 39.8 acres 

in Segment 2 and 37.3 acres in Segment 3. Temporary impacts on this unit include 28.2 acres in Segment 

2 and 9.4 acres in Segment 3. Permanent impacts on the Ivanpah Critical Habitat Unit include 212 acres 

in Segment 3 and 2.1 acres in Segment 4. Temporary impacts on this unit include 57.7 acres in Segment 

3 and 11.7 acres in Segment 4. 

In addition, the DesertXpress EIS evaluated a median-running alignment for Segments 2 and 3; 

therefore, the impacts on critical habitat in these Segments have already been evaluated. Due to the 

presence and operation of the roadway, the PCEs that define the Desert Tortoise Critical Habitat Units 

(sufficient space to support populations, sufficient quality and quantity of forage species, suitable 

substrates for burrowing, and habitat protected from disturbance and human-caused mortality) are not 

present or are severely degraded in the areas where the modified Project footprint occurs in critical 

habitat. 

Southwestern Willow Flycatcher Critical Habitat

The SCE Utility Corridor previously crossed the Mojave River in Victorville, which is designated as critical 

habitat for the southwestern willow flycatcher. This component is no longer a part of the modified 

Project; therefore, the Project would not affect Southwestern willow flycatcher critical habitat.

AREAS OF CRITICAL ENVIRONMENTAL CONCERN

An ACEC is a BLM designation that indicates areas with significant values that must be accommodated 

when BLM considers future management actions and land use proposals. Each ACEC is assigned a 

disturbance cap to quantify the maximum allowable acreage of permanent disturbance within the ACEC. 

Only permanent impacts that occur on land under BLM management within the ACECs are subject to the 
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ACEC disturbance caps. Temporary impacts on lands managed by BLM within ACECs are subject to 

restoration requirements but do not count towards disturbance caps. Coordination with BLM is ongoing 

to determine the status of ACEC disturbance caps relative to the modified Project. 

Impacts on the Cronese Basin and Halloran Wash ACECs were evaluated in the DesertXpress EIS. In 

September 2016, the BLM issued the ROD for the DRECP, which added five new ACECs within the 

modified Project footprint (discussed below); therefore, impacts to these ACECs were not previously 

evaluated in the DesertXpress EIS. Table 4.2-8 summarizes the modified Project-related impacts to lands 

under BLM management within ACECs and their associated disturbance caps.

Table 4.2-8 Modified Project Footprint Impacts to Lands Under BLM Management within ACECs

ACEC

BLM Acres within 

ACEC

ACEC Disturbance Cap 

% (acres)

Permanent

(acres)

Temporary

(acres)

Total Project 

Impacts (acres)

Cronese Basin 8,470 1% (85) 1.9 0.4 2.3 

Halloran Basin 1,740 0.5% (9) - - - 

Superior-Cronese 330,670 0.5 % (1,653) 3.8 3.5 7.4 

Ivanpah 78,190 1% (781) 64.9 194.9 259.8 

Shadow Valley 197,530 0.5% (988) 91.6 30.8 122.4 

Northern Lucerne 

Wildlife Linkage 21,900 0.5% (110) 8.5 - 8.5 

Soda Mountains 

Expansion 16,720 1% (167) 110.3 21.6 131.9 

Total 655,220 N/A 281.0 251.2 532.2 

Cronese Basin ACEC

Impacts on this ACEC were previously evaluated in the DesertXpress EIS, and based on modified Project

footprint impacts, have been substantially reduced in terms of acreage because the footprint and 

associated ACEC impacts are now within the I-15 freeway corridor. The total size of this ACEC is 8,470 

acres, and the ACEC disturbance cap is one percent of total acreage, which would be 85 acres. Within 

this ACEC, the BLM manages approximately 2.3 acres of land where the modified Project footprint (1.9

acres permanent and 0.4 acre temporary) is located within the I-15 freeway corridor. 

Halloran Basin ACEC

The Preferred Alternative from DesertXpress EIS included temporary impacts on this ACEC. Based on the 

modified Project footprint, impacts on this ACEC are no longer expected.

Superior-Cronese ACEC

This ACEC was established because it provides high density desert tortoise habitat, provides critical 

tortoise habitat connectivity, and corresponds to the general boundaries identified by the Desert 

Tortoise (Mojave Population) Recovery Plan. The majority of this ACEC overlaps with the boundary of 

the Superior-Cronese Critical Habitat Unit. The impacts on this ACEC occur in Segments 2 and 3 primarily 

where the modified Project rail alignment occurs within the I-15 freeway, overpass interchanges, and

temporary construction areas associated with an autotransformer site evaluated in the DesertXpress 

EIS. As stated previously, the natural resources are degraded within the modified Project footprint due 
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to the proximity to existing maintained roadway infrastructure, and they are unlikely to support specialstatus wildlife. The total size of this ACEC is 330,670 acres and the ACEC disturbance cap is 0.5 percent, 

which would be 1,653 acres. Within this ACEC, the BLM manages approximately 7.3 acres of land where 

the modified Project footprint (3.8 acre permanent and 3.5 acres temporary) is proposed. 

Ivanpah ACEC

This ACEC was established because it is a highly rich ecosystem that provides habitat for desert tortoise, 

desert bighorn sheep, American badger, Bendire’s thrasher, and several BLM sensitive plants. It also

provides a critical tortoise habitat linkage between the Mojave National Preserve and land managed by 

the Las Vegas BLM Field Office. The 2002 Northern and Eastern Mojave (NEMO) Desert Plan designated 

the Ivanpah Valley Tortoise Management Area. The majority of this ACEC overlaps with the boundary of 

the Ivanpah Critical Habitat Unit. The boundary of this ACEC extends into the north and west shoulder of 

the southbound I-15 freeway corridor, which has been degraded due to its proximity to the I-15

freeway. Impacts on this ACEC occur primarily in the Mountain Pass area and Nipton Road interchange 

where the ACEC encompasses the entire I-15 freeway corridor. The total size of this ACEC is 78,190 

acres, and the ACEC disturbance cap is 1 percent, which would be 781 acres. Within this ACEC, the BLM 

manages approximately 259.8 acres of land where the modified Project footprint (64.9 acres permanent 

and 194.9 acres temporary) is proposed. 

Shadow Valley ACEC

This ACEC was established because the area provides habitat and supports regionally important 

populations of desert bighorn sheep and desert tortoise, it is an important east-west migration corridor 

for bats and a Bat Conservation Area (under the 2002 NEMO Plan), and it provides important wildlife 

landscape connections. In addition, many culturally significant features occur within this ACEC. The 

impacts on this ACEC from the modified Project footprint are entirely within the Segment 3 of the I-15 

freeway corridor between Baker and Mountain Pass, mostly related to the facilities near the I-15 

freeway interchanges. The natural resources in this ACEC are degraded within the modified Project

footprint due to the proximity to existing maintained roadway infrastructure and are unlikely to support 

special-status wildlife. The total size of this ACEC is 197,530 acres, and the ACEC disturbance cap is 0.5

percent, which would be 988 acres. Within this ACEC, the BLM manages approximately 122.4 acres of 

land where the modified Project footprint (91.6 acres permanent and 30.8 acres temporary) is 

proposed.

Northern Lucerne Wildlife Linkage ACEC

This ACEC was established because it is considered a regionally significant area—providing habitat for 

bighorn sheep, golden eagles, desert tortoise, prairie falcons, and numerous sensitive plant populations

and because the area provides critical links for wildlife populations to the north and south. 

The modified Project footprint (including the Dale Evans Station and OMSF site) is within the 

Stoddard/Johnson Valley Special Recreation Management Area (SRMA) and the Granite Mountains 

Recreation Management Zone (RMZ). The SRMA and Granite Mountains RMZ were established to 

provide long-term recreation opportunities along the urban interface with adjacent communities. This 

includes a range of different types of trails and day use experiences ranging from Off-Highway Vehicle 

(OHV) touring to family hiking excursions.

The land within the Dale Evans Station and OMSF site was included in the ACEC because of its potential 

to meet the desired future condition objectives in the ACEC Special Unit Management Plans. However, 
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the BLM does not own or manage the land where the Dale Evans Station and OMSF site would be 

located, and the habitat and wildlife movement value is degraded and of lower quality than other areas 

of the ACEC because of its adjacency to the I-15 freeway and previous grazing land uses. The natural 

resources in the I-15 freeway corridor portion of the ACEC are degraded within the modified Project 

footprint due to the proximity to existing maintained roadway infrastructure, and they are unlikely to 

support special-status wildlife. The total size of this ACEC is 21,900 acres, and the ACEC disturbance cap 

is 0.5 percent, which would be 110 acres. Within this ACEC, the BLM manages approximately 8.5 acres of 

land where the modified Project footprint (8.5 acres permanent and 0 acres temporary) is located within 

the I-15 freeway corridor. 

Soda Mountains Expansion ACEC

This ACEC was established because the area provides important plant and wildlife connectivity between 

surrounding Wilderness and Wilderness Study Areas, which encompass large blocks of intact habitat. 

The modified Project footprint included nearly 144 acres of permanent impacts and 45 acres of 

temporary impacts because of the rail alignment and facilities in Segment 3, which are entirely within 

the I-15 freeway corridor. The I-15 freeway corridor acts as the southern/eastern boundary of this ACEC. 

The natural resources in the ACEC are degraded within the modified Project footprint due to the 

proximity to existing maintained roadway infrastructure, and they are unlikely to support special-status 

plants and wildlife. The amount of BLM acres within this ACEC is 16,720 acres, and the ACEC disturbance 

cap is one percent, which would be 167 acres. Within this ACEC, the BLM manages approximately 131.9

acres of land where the modified Project footprint (110.3 acres permanent and 21.6 acres temporary) is 

located within the I-15 freeway corridor. 

5.0 Mitigation Measures

The mitigation measures from the DesertXpress ROD are included below and have been separated into 

two sections based on where they originated: the USFWS BO (Desert Tortoise-Specific Measures from 

The Biological Opinion), and the DesertXpress EIS (General Mitigation Measures). 

DESERT TORTOISE-SPECIFIC MEASURES FROM THE BIOLOGICAL OPINION

As discussed in Section 2.0, FRA submitted a letter to the USFWS on July 20, 2020 seeking concurrence 

that the Project modifications do not require reinitiation of formal consultation under Section 7. This 

letter proposed revised BO mitigation measures based on the Project modifications; for example, by 

specifying that such mitigation measures would only apply on suitable desert tortoise habitat outside of 

the I-15 freeway ROW. These updated mitigation measures will be confirmed through consultation with 

the USFWS and documented in accordance with Section 7 of the ESA. Revisions that may occur through 

this coordination process are discussed in bold following the applicable BO measures listed below.

Mitigation Measure DT-1 

Prior to the commencement of grading activities, the Applicant DesertXpress Enterprises, LLC shall 

ensure all personnel working within the Project area attend an environmental awareness training 

program. The program will be presented by biologists authorized by the United States Fish and Wildlife 

Service (USFWS; hereafter “authorized biologists”) and include information on the life history of the 

desert tortoise, the legal protection it is afforded by the Endangered Species Act, the definition of take 

for listed species, measures to protect the desert tortoise, reporting requirements, specific measures 

that each worker will need to employ to avoid adverse impacts on desert tortoises, a detailed 

description of environmental Project commitments as described in the decision records (i.e., record of 
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decision), right-of-way grants, and biological opinion, and penalties for violation of Federal and state 

environmental laws.

Mitigation Measure DT-2 

The Applicant DesertXpress Enterprises, LLC shall ensure an authorized biologist will be on site during 

any construction activity within or near desert tortoise habitat to ensure the implementation and 

compliance of environmental commitments and avoidance measures.

Mitigation Measure DT-3 

The Applicant DesertXpress Enterprises, LLC shall ensure the authorized biologists have the authority to 

stop work if dangers to desert tortoises arise, and to allow work to proceed after the hazard has been 

removed. The Applicant DesertXpress Enterprises, LLC shall notify the Southern Nevada and Ventura 

USFWS Offices, BLM Offices, and the California Department of Fish and Game of any desert tortoise 

injury or death resulting from Project-related activities.

Mitigation Measure DT-4 

The Applicant DesertXpress Enterprises, LLC shall ensure, as part of the monitoring, that an authorized 

biologist checks construction areas immediately before construction activities each day to ensure that 

no desert tortoise has moved into the construction area. If desert tortoises are discovered within the 

construction area, the authorized biologist shall relocate the desert tortoises to adjacent habitat 

approximately 300 feet from the limit of disturbance (i.e., beyond the 162.5-foot temporary 

construction area).

Mitigation Measure DT-5 

The Applicant DesertXpress Enterprises, LLC will ensure the authorized biologists properly implement 

protective measures, records and reports desert tortoise and sign observations in accordance with 

approved protocol, reports incidents of noncompliance in accordance with the biological opinion and 

other relevant permits and authorizations, and moves desert tortoises from harm‘s way and place these 

animals in adjacent habitat approximately 300 feet of the limit of disturbance.

Mitigation Measure DT-6 

The Applicant DesertXpress Enterprises, LLC shall confine all construction activities to the designated 

work areas. Grubbing of vegetation will only be done to the extent necessary for construction and will 

be limited to areas designated for that. Overnight parking and storage of equipment and materials will 

be limited to previously disturbed areas or areas identified in the BLM right-of-way grant.

Mitigation Measure DT-7 

The Applicant DesertXpress Enterprises, LLC shall restrict all vehicle traffic to existing paved roads and 

the Project alignment within the permanent or temporary construction area. Disturbance beyond the 

construction area would be prohibited except in emergency situations.

Mitigation Measure DT-8 

The Applicant DesertXpress Enterprises, LLC shall not allow speeds in excess of 15 miles per hour for 

construction vehicles within sensitive species habitat.
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Mitigation Measure DT-9 

The Applicant DesertXpress Enterprises, LLC shall implement a litter-control program during 

construction. The program will include the use of covered, common raven-proof trash receptacles, daily 

removal of trash from work areas to the trash receptacles, and 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.

Mitigation Measure DT-10 

The Applicant DesertXpress Enterprises, LLC will promptly remove all road-killed animals within the 

Project construction area and the permanent rail alignment to reduce the adverse effects associated 

with predation of desert tortoise by common ravens (Corvus corax).

Mitigation Measure DT-11 

The Applicant DesertXpress Enterprises, LLC will not permit pets or firearms in the work area.

Mitigation Measure DT-12 

The Applicant DesertXpress Enterprises, LLC shall take both pre- and post-construction photographs to 

document sensitive habitat conditions within the limits of Project disturbance.

Mitigation Measure DT-13 

During construction, the Applicant DesertXpress Enterprises, LLC will perform weekly inspections and 

weed removal/control during the growing season of all construction areas, rail alignment, and facilities. 

Following the completion of construction activities, from March through August, the Applicant

DesertXpress Enterprises, LLC will continue monitoring and removal monthly during the first 2 years of 

operation and quarterly for the life of the facility. Weed removal and control will consist of physical 

control methods (e.g., hand pulling, hoeing, etc.) or herbicide application. A provision of this measure 

requires preparation of an invasive weed monitoring and treatment plan that would be applicable to all 

lands affected by the proposed action. This weed control plan will be developed in cooperation with FRA 

and BLM to ensure that weed control and removal activities do not affect desert tortoises. The use of 

herbicides to control weeds within the Project construction and operation area will be coordinated with 

biologists of the BLM, the California Department of Fish and Game, and the Nevada Department of 

Wildlife (NDOW) to ensure the application does not affect desert tortoises. In instances where desert 

tortoises may come into contact with herbicide, the plan will require manual removal of individual 

plants. The FRA will ensure the same methods and caution will occur on lands within the action area 

that are outside of those managed by the BLM.

Mitigation Measure DT-14 

The Applicant DesertXpress Enterprises, LLC shall develop and implement a vegetation and topsoil 

removal and restoration plan to reduce impacts on biological resources. The plan shall include a 

requirement for the Applicant DesertXpress Enterprises, LLC to remove and stockpile construction area 

topsoil prior to initiating construction and replaced within areas of temporary disturbance once 

construction is complete. Any permanent topsoil stabilization measures will be constructed and 

maintained within the permanent right-of-way. These measures may include, but are not limited to, the 

use of geo-textile mats or rip-rap to in areas of high erosion potential.
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Mitigation Measure DT-15 

The Applicant DesertXpress Enterprises, LLC shall install and maintain rice wattles, straw wattles, and silt 

fencing along all construction areas to prevent sediment from being transported off of the right-of-way 

during construction. The Applicant DesertXpress Enterprises, LLC shall employ permanent stabilization 

measures upon completion of construction along washes and in other areas of potential erosion.

Mitigation Measure DT-16 

To minimize adverse effects to the desert tortoise, the Applicant DesertXpress Enterprises, LLC fence the 

boundary of the Victorville Passenger Station and the Victorville Dale Evans Station and OMSF site with 

permanent desert tortoise exclusion fencing. The Applicant DesertXpress Enterprises, LLC shall install 

desert tortoise guards at gated entries to prevent desert tortoises from gaining entry to the Project

sites. The Applicant DesertXpress Enterprises, LLC shall also fence the temporary construction areas, the 

Baker MOW facility, autotransformers paralleling sites and substations, the construction areas for the 

utility corridors, and the rail alignment‘s temporary construction area, with temporary desert tortoise 

fencing prior to clearance surveys and ground disturbance. Proposed construction sites along the 

alignment that are not located in desert tortoise habitat (i.e., within Barstow, Baker, and Las Vegas) will 

not be fenced.

• The locations requiring permanent or temporary desert tortoise fencing will be updated during 

Section 7 coordination with the USFWS. Most of the modified Project footprint is within the I-15 

freeway median, which the USFWS considers unsuitable desert tortoise habitat. 

Mitigation Measure DT-17 

To ensure the clearance of all desert tortoises from all potential habitat areas, the Applicant

DesertXpress Enterprises, LLC shall conduct clearance surveys using service-authorized desert tortoise 

biologists as required by the Service.

• The locations requiring preconstruction clearance surveys will be defined during Section 7 

coordination with the USFWS. Most of the modified Project footprint is within the I-15 freeway 

median, which the USFWS considers unsuitable desert tortoise habitat. 

Mitigation Measure DT-18 

The Applicant DesertXpress Enterprises, LLC shall include the installation of temporary desert tortoise 

fencing around the perimeter prior to the commencement of on-site construction as part of desert 

tortoise relocation from the Project area. Installation of the fencing will be monitored by an authorized 

biologist to ensure that desert tortoises are not killed or injured during this activity. Temporary desert 

tortoise fencing will be installed in areas of construction that are beyond the perimeter of the right-ofway or in areas where construction staging will occur. Desert tortoise guards will be installed at 

construction area entry points and permanent rail alignment maintenance access points. After 

installation, the fence will be regularly inspected to ensure its integrity. The Applicant DesertXpress 

Enterprises, LLC will ensure that cross-country travel for construction purposes outside of the areas of 

desert tortoise fencing is prohibited.

Mitigation Measure DT-19 

In areas where high vehicular construction traffic is expected (such as temporary construction areas), 

desert tortoise exclusionary fencing may require the supplemental use of a desert tortoise guard. 

Locations of such guards will be determined by an authorized biologist. This device resembles a cattle 
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guard and is positioned at ground level and connected to the exclusionary fencing to prohibit desert 

tortoise from crossing into the construction area but allowing the passage of construction vehicles. The 

guard would be maintained throughout its use during the construction process by the Applicant

DesertXpress Enterprises, LLC. Such maintenance would require the presence of an authorized desert 

tortoise biologist. The guard would have a clear escape route away from construction activity for any 

desert tortoise that should fall into the guard. The guard would be inspected daily for desert tortoise 

and to ensure the escape route is free of obstruction. The guard would also be cleared of debris that 

may allow desert tortoise passage across the guard and into a construction area.

Mitigation Measure DT-20 

The Applicant DesertXpress Enterprises, LLC shall ensure only biologists authorized by the USFWS will 

handle desert tortoises and follow the guidelines within the Desert Tortoise Field Manual. Desert 

tortoises found within the Project area will be removed and relocated to undisturbed suitable habitat 

beyond the construction site and within their own territory, where they may be familiar with alternate 

burrows. If no burrows are available, the Applicant DesertXpress Enterprises, LLC shall create artificial 

burrows following the guidelines within the Desert Tortoise Field Manual.

Mitigation Measure DT-21 

After installation of the temporary fencing, the Applicant DesertXpress Enterprises, LLC shall survey the 

entire Project area for desert tortoises. The survey shall be conducted by an authorized biologist. 

Following the procedures and precautions outlined in the Desert Tortoise Field Manual, all desert 

tortoise pallets and burrows within the survey areas will be examined and excavated by hand, either by 

or under the direct supervision of an authorized biologist, and collapsed to prevent re-entry.

Mitigation Measure DT-22 

The Applicant DesertXpress Enterprises, LLC shall ensure an authorized biologist will be present during 

all initial top soil removal, blading, or grading activities within the Project area. During Project

implementation, the Applicant DesertXpress Enterprises, LLC shall ensure all workers will inform the 

authorized biologist if a desert tortoise is found within or near Project areas. All work in the vicinity of 

the desert tortoise, which could injure or kill the animal, will cease and it will be observed until it is 

moved from harm‘s way by the authorized biologist.

Mitigation Measure DT-23 

The authorized biologist or Wworkers will inspect for desert tortoises under vehicles and equipment 

before such equipment is moved. If a desert tortoise is present, the worker will wait for it to move out 

from underneath the vehicle or the authorized biologist will be contacted to remove it.

Mitigation Measure DT-24 

The Applicant DesertXpress Enterprises, LLC will replace any previously installed permanent desert 

tortoise exclusionary fencing along Interstate 15 that is removed during Project construction.

Mitigation Measure DT-25 

The Applicant shall implement minimization measures for potential impacts to downstream habitat from 

Segment 4C (if constructed), which may include the use of tunnels, aerial crossing structures, at-grade 

overcrossing structures, and culverts. At a minimum, the Applicant shall avoid all ephemeral drainages 

equal to or greater than 4 feet wide with these types of structures. Where tunnels and aerial crossing 

structures would be used, drainages less than 4 feet in width would also be avoided. If support piles or 
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piers are necessary to support over crossing structures these structures would be located outside of the 

drainage being over crossed. Authorized biologists would be present during construction to ensure 

impacts to drainages are avoided or, where an impact is unavoidable, ensure the impact is minimized 

and the natural substrate of the drainage that has been disturbed is re-established to original grade and 

with natural substrate materials within the drainage channel. In addition to the ephemeral drainages 

over crossed, drainages established (created) or re-established as part of the Project‘s compensatory 

mitigation for replacement of affected waters of the United States or State of California would be

monitored by an agency-approved biologist for a minimum of 5 years to ensure that agency-approved 

performance standards are met.

• This mitigation measure no longer applies to the Project as the modified Project does not carry 

forward Segment 4C and would follow the I-15 freeway median through Mountain Pass.

Mitigation Measure DT-26

In addition to habitat restoration, the Applicant DesertXpress Enterprises, LLC will compensate for 

habitat disturbance through payment of a per-acre fee for disturbance of desert tortoise habitat in 

California and Nevada. These funds will be paid to the BLM and used for management actions expected 

to provide a benefit to the desert tortoise over time. Actions may involve habitat acquisition, population 

or habitat enhancement, increasing knowledge of the species’ biological requirements, reducing loss of 

individual animals, documenting the species’ current status and trends, and preserving distinct

population attributes. Specific actions to be funded will be determined during annual meetings between 

the BLM and the USFWS to identify and prioritize management actions, which may include 

implementation of range wide monitoring of desert tortoises.

TERMS AND CONDITIONS OF THE BIOLOGICAL OPINION SPECIFIC TO DESERT TORTOISE

Mitigation Measure DT-27 

To ensure that the measures proposed by the FRA and the Applicant DesertXpress Enterprises, LLC are 

effective and are being properly implemented, the FRA or the Applicant DesertXpress Enterprises, LLC

must contact USFWS immediately if it becomes aware that a desert tortoise has been killed or injured by 

Project activities. At that time, the Applicant DesertXpress Enterprises, LLC, in coordination with the 

FRA, must review the circumstances surrounding the incident with the USFWS to determine whether 

additional protective measures are required. Project activities may continue during the review, provided 

that the proposed protective measures in the Project description and any appropriate terms and 

conditions of this biological opinion have been and continue to be fully implemented.

If five desert tortoises are injured or killed as a result of construction of the Project, the FRA shall reinitiate consultation on the Project, pursuant to the implementing regulations for section 7(a)(2) of the 

Endangered Species Act at 50 Code of Federal Regulations 402.16.

• The amount of take may be modified based on Section 7 consultation. 

Mitigation Measure DT-28 

If two desert tortoises are injured or killed as a result of operation and maintenance of the Project in any 

calendar year, the FRA shall re-initiate consultation on the Project, pursuant to the implementing 

regulations for Section 7(a)(2) of the Endangered Species Act at 50 Code of Federal Regulations 402.16.

• The amount of take may be modified based on Section 7 consultation.
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Mitigation Measure DT-29 

The Applicant DesertXpress Enterprises, LLC shall monitor, during construction and operation, the 

integrity of all desert tortoise exclusion fencing on a regular basis and following any rain events that 

result in surface flow of water in washes within the action area.

Mitigation Measure DT-30 

The Applicant DesertXpress Enterprises, LLC shall use culverts that allow effective passage of desert 

tortoises but are large enough that desert tortoises are unlikely to use the culverts as burrows. The 

USFWS has estimated that any box culvert must be 3 feet on a side and pipe culverts 3 feet in diameter 

and recommends that box culverts be used because desert tortoises are less likely to use them as 

burrows. At a minimum, culverts would need to be large enough. The Applicant DesertXpress 

Enterprises, LLC shall ensure regular maintenance of the culverts so desert tortoises do not use 

accumulated debris to construct burrows. If a culvert under the rail line is tied to an existing culvert 

under Interstate 15 or the Union Pacific Railroad, the Applicant DesertXpress Enterprises, LLC, with 

approval from the FRA, may forego these specifications if they are incompatible with the existing 

culverts.

Mitigation Measure DT-31 

The Applicant DesertXpress Enterprises, LLC shall use culverts that will not entrap desert tortoises or 

block their passage. Specifically, all erosion control devices must be constructed and maintained in a 

manner that allows desert tortoises to enter and leave them freely.

Mitigation Measure DT-32 

The Applicant shall install a sufficient number of culverts in Segment 2C where it deviates from 

Interstate 15 (excluding on the dry lake bed), to ensure any desert tortoise whose home range occurs 

across the action area could continue to access both sides easily. In general, the distance between 

culverts must be no greater than 0.25 mile unless topography is an obstacle.

• This measure is no longer applicable because Segment 2C is no longer a part of the modified 

Project. 

Mitigation Measure DT-33 

The Applicant DesertXpress Enterprises, LLC shall ensure authorized biologists survey areas that could 

become isolated from the main body of habitat where the alignment deviates slightly from the freeway 

(e.g., at off-ramps). If desert tortoises are present and construction of the Project may disrupt their 

behavior or if a culvert or other access to the main body of habitat does not exist or will not be 

provided, the authorized biologist must relocate them to the side of the rail line that is adjacent to the 

main body of habitat. In any event of uncertainty, the authorized biologist must contact the Service for 

guidance prior to moving the desert tortoise; during this time, the authorized biologist may install 

fencing around the area of the desert tortoise‘s burrow so he or she may find it again.

Mitigation Measure DT-34

The Applicant DesertXpress Enterprises, LLC shall design all new utility lines and ancillary structures 

associated with the Project in a manner that will reduce the likelihood of nesting by common ravens. 

The Applicant DesertXpress Enterprises, LLC, as appropriate, must monitor these utility lines and 

ancillary structures to ensure the effectiveness of their measures and implement adaptive management, 

in coordination with the Service, if the initial measures are unsuccessful. The Applicant DesertXpress 
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Enterprises, LLC must ensure that any common ravens nests established on new utility lines and 

ancillary structures are removed within one year at a time when they are inactive.

Mitigation Measure DT-35 

During construction of the Segment 4C rail line (if constructed), if desert tortoises that have been 

translocated from the Ivanpah solar plant site need to be moved from harm‘s way, the Applicant shall 

coordinate their capture and movement with the BLM to ensure that the health and welfare of these 

animals is not compromised. Prior to the onset of construction, the Applicant must contact the BLM to 

establish appropriate protocols to follow in the event these animals are encountered.

• This measure is no longer applicable because Segment 4C is no longer part of the modified Project. 

Mitigation Measure DT-36 

By January 31 of any year the proposed action is under construction and during its operation, the FRA 

must provide a report to USFWS) that provides details on the effects of the action on the desert tortoise. 

Within 60 days of the completion of the proposed action, the FRA must provide a summary report that 

provides, in addition to the following information, a complete overview of the amount of habitat 

disturbed and the number of desert tortoises that were taken. The Applicant DesertXpress Enterprises, 

LLC shall furnish all of these reports to the FRA no less than 15 days prior to the required USFWS 

submittal. These reports shall include information on any instances when desert tortoises were killed, 

injured, or handled, the circumstances of such incidents, and any actions undertaken to prevent similar 

instances from re-occurring. In addition, the reports should include any recommendations that would 

facilitate the implementation of the protective measures while maintaining protection of the desert 

tortoise and the names of any monitors who assisted the authorized biologist and an evaluation of the 

experience they gained on the Project. 

Mitigation Measure DT-37 

Within 3 days of locating any dead or injured desert tortoises, the Applicant DesertXpress Enterprises, 

LLC, in coordination with the FRA, shall notify the Ventura Office of USFWS by telephone (805 644-1766) 

and by facsimile (805 644-3958) or electronic mail. The report must include the date, time, and location 

of the carcass, a photograph, cause of death, if known, and any other pertinent information.

Mitigation Measure DT-38 

The Applicant DesertXpress Enterprises, LLC shall take care in handling dead desert tortoises to preserve 

biological material in the best possible state for later analysis. If desert tortoises are killed by Project

activities, USFWS will instruct the Applicant DesertXpress Enterprises, LLC regarding the final disposition 

of the carcass.

GENERAL MITIGATION MEASURES FROM THE DESERTXPRESS EIS

Revisions to these General Mitigation Measures provided in the DesertXpress EIS are included as 

strikeout underline following the applicable measure. 

Mitigation Measure BIO-1: Conduct Mandatory Environmental Awareness Training Program

Prior to the commencement of Project-related activities, The Applicant DesertXpress Enterprises, LLC

shall ensure all personnel working within the Project area attend an environmental awareness training 

program. The program shall be presented by authorized biologists and include information on the life 

history of special-status species that may be encountered during construction activities, the legal 
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protection for each species, the definition of “take” for listed species, measures to protect special-status 

species, reporting requirements, specific measures that each worker shall need to employ to avoid 

adverse effects to individual sensitive species, The program will be prepared by biologists approved by 

the USFWS and/or the “authorized biologist” and can be presented in-person or digitally (i.e. Microsoft 

PowerPoint or similar means). Temporary personnel (including delivery drivers, concrete truck drivers, 

mechanics/refueling trucks, port-a-toilet pump trucks, etc.) will not be required to attend the training 

program such that they are instructed by trained Project personnel not to operate or enter into areas 

designated as desert tortoise habitat, defined below. Each person attending the training will be required 

to sign a training sheet, which will be kept on file in the Project trailer. The program will include 

information on the life history of the desert tortoise, the legal protection it is afforded by the 

Endangered Species Act, the definition of take for listed species, measures to protect the desert tortoise, 

reporting requirements, specific measures that each worker will need to employ to avoid adverse 

impacts on desert tortoises, a detailed description of environmental Project commitments as described 

in the decision records (i.e., Record Of Decision), ROW grants, and biological opinion, and penalties for 

violation of federal and state environmental laws.

Mitigation Measure BIO-2: Conduct Preconstruction Surveys and Install Environmental Fencing

The Applicant DesertXpress Enterprises, LLC shall undertake preconstruction surveys for special-status 

species; these surveys shall be conducted by qualified biologists (i.e., one or more third party 

contractor(s) approved by the USFWS) prior to the start of construction. Preconstruction surveys shall 

be tailored for specific species based on the species biology, natural history, suitable habitat, and 

regulatory requirements. The locations for any individual or population of sensitive species within the 

limit of disturbance shall be documented with a GPS unit and reported to the state and federal 

regulatory agencies.

Mohave ground squirrel surveys are only valid for 12 months. Therefore, they shall be done no more 

than 12 months prior to the start of construction within suitable habitat in a particular area. If no 

Mohave ground squirrels are found during the surveys, no additional mitigation would be required.

Mojave fringe-toed lizard surveys shall occur no more than 24 hours prior to the start of construction. 

Surveys shall be conducted within suitable habitat within the work area and a 100-foot buffer. Any 

Mojave fringe-toed lizards observed in the work area shall be allowed to move out of the work area. 

Those that become trapped in the work area shall be captured and moved to nearby suitable habitat 

outside of the work area.

Qualified biologists shall conduct preconstruction surveys for banded Gila monsters no more than 24 

hours prior to the start of construction within all suitable habitat in Segments 3 and 4. Surveys shall be 

conducted within suitable habitat within the work area and a 100-foot buffer. Any Gila monsters 

observed within the work areas shall be allowed to move out of the work area and those that become 

trapped within the work area shall be carefully moved to nearby suitable habitat by a qualified biologist. 

The handler shall have the applicable and necessary permit to handle and move lizards. Qualified 

biologists shall conduct preconstruction surveys for BLM-sensitive and Clark County Multiple-Species 

Habitat Conservation plan (HCP) covered reptile species no more than 48 hours prior to the start of 

construction in areas of suitable habitat. Surveys shall be conducted within the work area and include a 

100-foot buffer. Any sensitive reptile species observed within the work areas shall be allowed to move 

out of the work area and those that become trapped within the work area shall be very carefully moved 

to nearby suitable habitat by a qualified biologist. 
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The Applicant DesertXpress Enterprises, LLC shall implement the following measures, to avoid 

disturbance of tree, shrub- or ground-nesting special-status and migratory birds and raptors:

• If construction activities are scheduled to occur during the breeding season (generally between 

February 15March 1 and September 1August 15), a qualified wildlife biologist shall conduct focused 

nesting surveys within the appropriate habitat and an appropriate buffer distance up to 0.25 mile 

from the limit of Project disturbance for nesting raptors.

• The focused surveys shall include tree- and shrub-nesting birds, ground-nesting birds, and cliffnesting birds. The surveys shall be conducted within the two-week period before initiation of 

construction activities in a particular area between February 15March 1 and September 1August 15. 

If no active nests are detected, then no additional mitigation would be required. 

• Follow-up surveys shall be required on a monthly basis during the breeding season. If surveys 

indicate that active nests are present in any areas that would be directly affected by construction 

activities, a no-disturbance buffer would be established around the site to avoid disturbance or 

destruction of the nest site until after a wildlife biologist determines that the young have fledged 

(usually late June to mid-July). The extent of these buffers shall be determined by a wildlife biologist 

in consultation with the CDFW in California and the NDOW in Nevada and will depend on the level of 

noise or construction disturbance, line of sight between the nest and the disturbance, ambient 

levels of noise and other disturbances, and other topographical or artificial barriers. These factors 

shall be analyzed to make an appropriate decision on buffer distances.

A qualified biologist shall conduct preconstruction surveys for active burrows according to the CDFW 

Staff Report on Burrowing Owl Mitigation (CDFW 2012). guidelines for burrowing owl (1993 and 1995).

The preconstruction surveys shall be conducted by a qualified biologist 14 days and 24 hours before 

initiation of construction activities to locate active burrowing owl burrows within the work area and 

include a 250-foot buffer and within the 2-week period before initiation of construction activities to 

locate active burrowing owl burrows. The preconstruction surveys shall include a nesting season survey 

and a wintering season survey the season immediately preceding construction. If no burrowing owls are 

detected, no further mitigation would be required. 

Focused surveys for the presence of sensitive bat species shall be conducted in areas that provide 

suitable roosting or nursery habitat including trees, rock outcrops, and bridges. If a roosting site is active 

and cannot be avoided, the Applicant DesertXpress Enterprises, LLC shall consult with a bat expert in 

conjunction with the CDFW in California and the NDOW in Nevada to develop appropriate exclusion 

methods. If it is determined that a nursery sites is active and cannot be avoided, construction activities 

that would disturb the nursing bats shall be delayed until the breeding cycles for the bats are 

completed. The Applicant DesertXpress Enterprises, LLC shall consult with a bat specialist in order to 

determine the breeding cycle for bats. The Applicant DesertXpress Enterprises, LLC shall document the 

results of any exclusion or avoidance of roosting/nursery sites for bats.

Qualified biologists shall conduct preconstruction surveys for American badger no more than 48 hours 

prior to the start of construction. Surveys shall be conducted within the work area and a 100-foot buffer. 

Any American badgers observed in the work area shall be allowed to leave the work area.

Construction activities conducted within suitable desert bighorn sheep habitat in the Mountain Pass 

area of the Project shall not occur during the period of the year when desert bighorn sheep are lambing 

(from January 1 to April 30). If construction activities must occur during the desert bighorn sheep 

lambing period, pre-construction surveys for lambing desert bighorn sheep shall be conducted prior to 
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construction. If lambing desert bighorn sheep are found, then the Applicant DesertXpress Enterprises, 

LLC shall consult with the BLM and the CDFW to identify appropriate avoidance measures.

Qualified botanists shall conduct preconstruction surveys for sensitive botanical species and invasive, 

non-native weed species prior to initiating construction of the Project. If sensitive botanical species are 

observed within the temporary construction area of effect, avoidance and minimization measures shall 

be applied by the Applicant DesertXpress Enterprises, LLC. 

Temporary environmental fencing shall be installed around sensitive biological and botanical resources 

prior to the commencement of on-site Project construction in order to avoid unnecessary adverse 

effects to the resource. These areas shall be signed for avoidance by construction equipment and 

personnel. USFWS- and BLM-approved desert tortoise exclusionary fencing shall be erected under 

supervision by an authorized biologist within portions of the Project that occur in desert tortoise habitat. 

Temporary desert tortoise fencing shall be installed in areas of construction that are beyond the 

perimeter of the right-of-way or in areas where construction staging would occur. This includes fencing 

all work areas, temporary equipment and vehicle yards, and material staging and storage areas, as 

defined in the biological opinion. Desert tortoise exclusionary fencing and clearance surveys shall be 

undertaken no more than 10 days prior to initiating construction activities. After installation of the 

temporary fencing, the entire Project area shall be surveyed for desert tortoises by an authorized 

biologist. Following the procedures and precautions outlined in the Desert Tortoise Council’s guidelines, 

all desert tortoise pallets and burrows within the survey areas shall be examined and excavated by hand, 

either by or under the direct supervision of an authorized biologist, and unoccupied features collapsed 

to prevent re-entry. After installation, the fence shall be regularly inspected to ensure its integrity. 

Desert tortoise encountered during preconstruction surveys shall be relocated off the Project based on a 

USFWS and BLM approved Project-specific Desert Tortoise Relocation Plan. At a minimum, the Desert 

Tortoise Relocation Plan shall require the desert tortoises found within the Project area be removed to 

undisturbed areas beyond the construction site and relocated within their own territory where they may 

be familiar with alternate burrows. If no natural burrows are available, artificial burrows shall be created 

following the Desert Tortoise Council’s guidelines. Only biologists authorized by the USFWS shall handle 

desert tortoises and shall follow the guidelines established by the Desert Tortoise Council.

The Applicant DesertXpress Enterprises, LLC shall install and maintain permanent exclusionary fencing 

along the open portion of the rail alignment in areas of suitable bighorn sheep habitat. The fencing shall 

be constructed to ensure that bighorn sheep cannot access the rails rail corridor. or any 

culverts/tunnels. In addition, prior to initiating construction, temporary exclusionary fencing shall be 

placed around all sensitive botanical species that occur within the temporary construction areas. These 

areas shall be signed for avoidance by construction equipment and personnel.

Mitigation Measure BIO-3: Conduct Construction Monitoring

The Applicant DesertXpress Enterprises, LLC shall implement the following measures during Project

construction:

• Qualified biologists shall be on site during any construction activity within or near special-status 

species habitat to ensure the implementation and compliance of environmental commitments and 

avoidance measures.

• The qualified biologist shall have the authority to stop work if dangers to desert tortoises or other 

special-status wildlife species arise and allow work to proceed after the hazard has been removed. 

The USFWS Southern Nevada and Ventura Ecological Services Offices, BLM Field Offices and the 

CDFW must be notified of any desert tortoise injury or death resulting from Project-related 
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activities. In addition, the USFWS Division of Law Enforcement shall also be notified in accordance 

with reporting requirements. As part of the monitoring, the biologists shall check construction areas 

immediately before construction activities each day to ensure that no special-status wildlife species 

have moved into the construction area. If tortoises are discovered within the construction area they 

shall be relocated by an authorized biologist based on the Desert Tortoise Relocation Plan.

• All construction activities shall be confined to the designated work areas. Grubbing of vegetation 

shall only be to the extent necessary for construction and shall be limited to areas designated for 

that. An authorized qualified biologist(s) shall be present during all initial brushing or grading 

activities within the Project area. Overnight parking and storage of equipment and materials would 

be limited to previously disturbed areas or areas identified in the BLM right-of-way grant.

• All vehicle traffic shall be restricted to existing roads or land management agency approved newly 

constructed roads. The Applicant DesertXpress Enterprises, LLC shall ensure that cross-country 

travel for construction purposes outside of the areas of desert tortoise fencing is prohibited.

• Construction vehicles within sensitive species habitat shall not exceed 15 miles per hour.

• A litter-control program shall be implemented during construction. The program shall include the 

use of covered, raven-proof trash receptacles, daily removal of trash from work areas to the trash 

receptacles, and proper disposal of trash in a designated solid waste disposal facility. Precautions 

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

• No pets or firearms shall be permitted in the work area.

• Both pre- and post-construction photographs shall be taken to document sensitive habitat 

conditions within the limits of Project disturbance.

• Trenches and holes shall be completely and securely covered by end of the workday. If the hole or 

trench is too large to be covered, then wildlife escape ramps shall be built such that any entrapped 

wildlife can escape on their own. Prior to the start of work on the next day, the approved biologist 

shall inspect any holes and trenches that have been covered or ramped to determine if wildlife have 

fallen in overnight. If non-listed wildlife is discovered within the hole or trench, the approved 

biologist will remove and relocate the individual out of the Project limits. If a listed species is 

discovered within a hole or trench, DesertXpress Enterprises, LLC will allow the animal to escape out 

of harm’s way. If the animal is not able to escape in its own, DesertXpress Enterprises, LLC shall stop 

work within the immediate vicinity and notify the appropriate resources agency before construction 

proceeds. 

Mitigation Measure BIO-4: Avoid the Dispersal of Invasive, Non-Native Weed Species into Uninfested 

Areas

To avoid the introduction or spread of invasive, non-native weed species into uninfested areas, the 

Applicant DesertXpress Enterprises, LLC shall incorporate the following measures into the Project plans 

and specifications:

• Use only certified, weed-free, imported erosion-control materials (or rice straw in upland areas).

• Coordinate with BLM field offices and the NPS to ensure that the appropriate best management 

practices (BMPs) are implemented.

• Educate construction supervisors and managers on weed identification and the importance of 

controlling and preventing the spread of invasive, non-native weed species.

• Clean equipment at designated wash stations before and after entering the Project construction 

area. Equipment shall be cleaned prior to entry to the Project site and upon demobilization.
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• An invasive, non-native weed species survey of the Project right-of-way, including temporary work 

areas, shall be completed prior to initiating Project construction. All areas disturbed by the Project

shall be surveyed using approximately 30-foot meandering transects. Populations of invasive, nonnative weed species shall be identified and mapped using global positioning systems (GPS).

• Develop an approved Invasive Weed Species Monitoring and Treatment Plan to detect and treat any 

noxious invasive, non-native weed species in the construction area. The plan shall include methods 

for monitoring, treating and reporting invasive, non-native weed species infestations within the 

construction area. The Invasive Weed Species Monitoring and Treatment Plan shall be drafted and 

submitted to the BLM prior to initiating construction as part of the BLM ROW grant requirements.

Mitigation Measure BIO-5: Confine Construction Equipment to a Designated Work Zone (Including 

Access Roads) at Each Project Site

The Applicant DesertXpress Enterprises, LLC shall clearly stake and flag the work zone prior to 

construction within areas of suitable habitat. During the environmental training program, construction 

personnel shall be informed about the importance of avoiding ground-disturbing activities outside the 

designated work area. During construction, the construction monitors and resource monitors shall

ensure that construction equipment and associated activities avoid any disturbance of native vegetation 

and sensitive resources outside the designated work zones. Contaminant run-off shall be contained 

within the temporary construction boundaries and clean-up efforts shall be initiated immediately. Cleanup procedures shall be coordinated with the responsible agency to ensure additional resource damage 

does not occur.

Mitigation Measure BIO-6: Reestablish Preconstruction Site Conditions to Allow Revegetation

The Applicant DesertXpress Enterprises, LLC shall restore disturbed areas of native vegetation to 

preconstruction site conditions. To ensure that effects on native plant species and communities are not 

long-term, the Applicant DesertXpress Enterprises, LLC shall stockpile and immediately replace native 

topsoil within the Project right-of-way, and reestablish natural site topography (including necessary 

amendments to soil structure) to allow natural colonization of plant species.

In both California and Nevada, the Applicant DesertXpress Enterprises, LLC shall relocate all succulents 

within the limits of disturbance to undeveloped BLM-administered public lands or maintain them within 

a temporary nursery (located within the right-of-way) and replant within the ROW as part of site 

restoration activities.

In areas that require immediate stabilization, non-vegetative techniques that allow native species to 

reestablish can be used, including use of weed- and disease-free mulch, erosion blankets, or rolled 

organic fiber material.

Erosion control seed mixes may be necessary on selected sites. If sites need to be stabilized through 

seeding, the seed mix would be composed entirely of native and locally occurring species appropriate 

for stabilizing local site conditions. All seed mixes shall be approved by the BLM, NPS, NDOT and Caltrans

prior to initiating restoration activities. Special attention shall be given to erosion control near 

ephemeral drainages and within playas. The Applicant DesertXpress Enterprises, LLC shall determine 

site-specific erosion control measures (non-vegetation or mechanical techniques) in consultation with a 

vegetation specialist and Project engineer.
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Mitigation Measure BIO-7: Retain and Stockpile Topsoil

The Applicant DesertXpress Enterprises, LLC shall remove native topsoil from areas of permanent 

disturbance outside of the Interstate 15 freeway ROW and stockpile within the Interstate 15 freeway

ROWright-of-way. To avoid altering local hydrologic conditions or flood flows, spoils materials shall not 

be placed in sensitive habitat areas or within or adjacent to ephemeral drainages. Prior to disturbance, 

native topsoil shall be excavated and stockpiled for later reapplication in native vegetation areas. 

Separate stockpiling areas shall be identified and clearly marked for each different vegetation type as 

appropriate. The exact depths shall be determined for each native vegetation type and depend upon the 

stratigraphy and soil profiles (estimated to be 6-12 inches in depth). The excavated soil depths shall 

exceed the restored soil depths to allow for soil compaction during placement. The stockpiled soil shall 

not be covered to minimize damage to propagation material from heated soil conditions but it shall be 

protected from construction activity and signed to identify it as a protected resource.

Mitigation Measure BIO-8: Restore Natural Site Topography

The Applicant DesertXpress Enterprises, LLC shall be responsible for restoring the natural site 

topography of temporarily disturbed areas to pre-Project contours. The restored topography shall mimic 

the pre-Project condition to the greatest extent possible. Minor modifications may be required to 

conform with post-Project site condition. Construction area soil compaction shall be treated using 

grubbing, raking, and other BLM-approved soil decompaction techniques as part of the Project

restoration. Proper compaction of the subsurface material and plow furrows is necessary to help 

prevent surface and subsurface migration of water along the plow or trench furrow, and to prevent 

trench settlement. The reapplied topsoil in the right-of-way temporary disturbance areas outside of the 

ROW shall be left in roughened condition to facilitate the establishment of vegetation and reduce the 

potential for erosion. Excessive passes of finish grading equipment that would compact topsoil shall be 

avoided. Upon completion of the grading operations, no further vehicular traffic shall be allowed, other 

than necessary mitigation planting equipment.

Mitigation Measure BIO-9: Implement Erosion Control Measures as Appropriate

The Applicant DesertXpress Enterprises, LLC shall prepare and implement an erosion control and 

restoration plan to control short-term and long-term erosion and sedimentation effects and to restore 

soils and native vegetation in areas temporarily affected by construction activities. The plan shall include 

requirements of applicable erosion control ordinances and grading permits and shall implement BMPs 

for erosion and sediment control as necessary. The erosion control plan shall be drafted and submitted 

to the BLM prior to initiating construction as part of the BLM ROW grant requirements.

In areas that require immediate stabilization, non-vegetative techniques that allow native species to 

reestablish can be used, including use of weed- and disease-free mulch, erosion blankets, or rolled 

organic fiber material. The use of such measures shall be identified in the Stormwater Pollution and 

Prevention Plan (SWPPP) for the Project or recommended by a soil or civil engineer based on slope, soil 

type, or other site factors as necessary and may be required later in the design phase.

Mitigation Measure BIO-10: Obtain a Tree or Plant Removal Permit from San Bernardino County and 

the Nevada Division of Forestry

The Applicant DesertXpress Enterprises, LLC shall obtain a Tree or Plant Removal Permit from San 

Bernardino County and the Nevada Division of Forestry. This permit is issued in compliance with San 

Bernardino County Development Code Subsection 88.01.050 for removal of regulated plants. The 
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Applicant DesertXpress Enterprises, LLC shall comply with all provisions of the Permit. A permit shall be 

required from the Nevada Division of Forestry and/or the BLM in order to relocate succulents within the 

Project alignment. The Applicant DesertXpress Enterprises, LLC shall also comply with the California 

Desert Native Desert Plants Act, consistent with pertinent BLM regulations.

Mitigation Measure BIO-11: Compensate for the Loss of Sensitive Vegetation Communities

The Applicant DesertXpress Enterprises, LLC shall compensate for the loss of Sensitive Vegetation 

Communities prior to initiating construction. Compensation ratios shall be based on site-specific 

information and determined through coordination with state and federal agencies (Caltrans, NDOT, the 

United States Army Corps of Engineers (USACE) and the BLM). This site-specific information will 

supplement the executed studies for the Project, including the 2010 botanical survey in California near 

Mountain Pass investigating the area where Segment 4C, if constructed, would be located.

Compensation should be provided at a minimum 1:1 ratio (1 acre restored or created for every 1 acre 

removed/disturbed) and may be a combination of onsite restoration/creation, offsite restoration, or 

mitigation credits. The Applicant DesertXpress Enterprises, LLC shall develop and implement a 

restoration and monitoring plan that describes enhancement of sensitive communities, creation, and 

monitoring over a select time period.

Mitigation Measure BIO-12: Conduct Preconstruction Surveys and Identify Sensitive Areas

The Applicant DesertXpress Enterprises, LLC shall mark specific areas of important riparian vegetation 

with orange fencing and the limits of disturbance narrowed to reduce effects to sensitive vegetation 

where the rail alignment crosses the Mojave Riverin the Mountain Pass area.

Mitigation Measure BIO-13: Avoid Known Special-Status Plant Populations during Project Design

To the extent possible, the Applicant DesertXpress Enterprises, LLC shall design the Project to avoid 

special-status plant populations, updating design-build Project plans accordingly. The Applicant

DesertXpress Enterprises, LLC shall comply with the minimum survey and mitigation standards as 

required by BLM Manual 6840-1. Where avoidance is infeasible, the Applicant DesertXpress Enterprises, 

LLC shall focus on minimizing the width of construction work areas in and around special-status plant 

populations. Before construction, special-status plant populations shall be demarcated with temporary 

orange construction fencing and posted as a restricted area. Depending on the proximity of the 

populations to the construction work area, populations shall be monitored to ensure adverse effects on 

special-status plant populations are avoided. If effects on special-status plant populations are 

unavoidable, the Applicant DesertXpress Enterprises, LLC shall implement Mitigation Measure BIO-14.

Mitigation Measure BIO-14: Compensate for Adverse Effects on Special-Status Plant Populations

If effects on a special-status plant population are unavoidable, the Applicant DesertXpress Enterprises, 

LLC shall coordinate with the USFWS to determine the appropriate mitigation strategy. If affected plants 

are listed under the federal ESA, the appropriate take permits would be obtained from USFWS. 

Currently accepted mitigation of effects on special-status plants includes acquisition and preservation of 

nearby occupied habitat, or habitat creation at a ratio determined by the regulatory agency. 

Transplantation of affected populations is not considered a viable mitigation option. Creation of habitats 

with high levels of endemism, such as vernal pools, is effective only with stringent agency management 

guidelines. The Applicant DesertXpress Enterprises, LLC shall coordinate with the USFWS to develop an 

effective mitigation and monitoring plan for specific vernal pool plants in conjunction with the 

construction of compensatory vernal pool habitat. Alternatively, the Applicant DesertXpress Enterprises, 
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LLC could acquire and preserve nearby high-quality occupied habitat, with the Applicant DesertXpress 

Enterprises, LLC responsible for the long-term habitat management. 

Mitigation Measure BIO-15: Prepare a Desert Tortoise Relocation Plan

The Applicant DesertXpress Enterprises, LLC shall develop a Desert Tortoise Relocation Plan in 

conjunction with USFWS Southern Nevada and Ventura Ecological Services Offices and the BLM, the 

NPS. The relocation plan shall outline procedures and protocols to follow when tortoises need to be 

relocated out of the areas of disturbance. The relocation plans shall include:

• Clearance procedures for construction areas;

• Relocation procedures;

• Procedures for determining the health of tortoises;

• Relocation areas;

• Methods that shall be used to manage and protect relocation areas;

• Monitoring for short-and long-term success of the plan; and

• Permitted activities.

Mitigation Measure BIO-16: Prepare Final Mitigation Monitoring Report

The Applicant DesertXpress Enterprises, LLC shall ensure that no more than 90 days after the completion 

of construction, the monitoring biologists prepare a report for USFWS, the BLM, and appropriate state 

agencies. The report shall include the effectiveness of mitigation measures, the results of 

preconstruction and construction monitoring including the number of desert tortoises excavated and 

moved.

Mitigation Measure BIO-17: Implement Mitigation Measures Outlined by the Regional USFWS 

Ecological Services Office to Protect Desert Tortoises

The Applicant DesertXpress Enterprises, LLC, in accordance with USFWS guidance, shall pay mitigation 

fees for disturbance to desert tortoise habitat on BLM administered public lands in Nevada.

Mitigation Measure BIO-18: Compensate for the Permanent Loss of Desert Tortoise Habitat

The Applicant DesertXpress Enterprises, LLC shall provide compensation for the permanent loss of 

desert tortoise habitat. Compensation for loss of habitat in California shall be provided by the Applicant

DesertXpress Enterprises, LLC according to requirements of the BLM and USFWS. Current requirements 

for loss of desert tortoise habitat are based on a formula of 5:1 inside Desert Wildlife Management 

Areas (DWMAs) inside desert tortoise designated critical habitat and 1:1 outside of desert tortoise

DWMAs designated critical habitat. For the purposes of the Project, changes to the compensation 

formula must be reviewed and approved by the USFWS and the NPS, BLM. 

For Project-related loss of habitat in Nevada, the Applicant DesertXpress Enterprises, LLC shall follow the 

mitigation measures outlined by the Regional USFWS Ecological Office for the protection of desert 

tortoises.

Mitigation Measure BIO-19: Construct Exclusion Fencing, Culverts, and Wildlife Crossings

The Applicant DesertXpress Enterprises, LLC shall install culverts under the proposed railroad line that 

match existing I-15 or Union Pacific Railroad (UPRR) culverts. Where the Project deviates from existing 

transportation facilities, the Applicant shall install culverts adequately designed to serve as wildlife 

crossings at natural drainage features and at appropriate intervals to allow for wildlife passage, 
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including, but not limited to, desert tortoises and other wildlife to pass under the proposed rail 

alignment. The Project design shall mimic existing conditions (in-line piers, height, and width) to ensure 

flow for natural drainages equal to or greater than four feet in width (as measured by the distance 

between the ordinary high water mark on each side of the drainage) during Project construction or 

operation in order to reduce potential effects to wildlife movement, including, but not limited to, desert 

tortoise and desert bighorn sheep. The bridges, culverts and fencing would be designed and spacing 

determined through coordination with the USFWS, BLM, Caltrans, and NDOT the NPS, the BLM, the 

California Department of Fish and Game (CDFG), the Nevada Department of Wildlife (NDOW), and the 

United States Environmental Protection Agency (EPA to ensure they meet agency wildlife standards.

Where Eexclusion fencing is installed, it would be designed in such a way to would be constructed 

parallel to the rail line and would direct tortoises and other wildlife species to the culverts.

Recommendations for wildlife crossings can be found in Wildlife Crossing Structure Handbook Design 

and Evaluation in North America,1 California Essential Habitat Connectivity Project2, and Areas of 

Conservation Emphasis3. 

Mitigation Measure BIO-20: Compensate for the Permanent Loss of Mohave Ground Squirrel Habitat

If Mohave ground squirrels are determined to be present in the Project area outside of the I-15 right-ofway, the Applicant DesertXpress Enterprises, LLC shall mitigate for the permanent loss of suitable 

habitat. Acreage of suitable habitats outside of the I-15 right-of-way that could be permanently affected

by the project. 

Mitigation Measure BIO-21: Avoid Active Burrows or Passively Relocate Owls

If burrowing owls are detected within 250 feet of proposed construction within the Project area, the 

Applicant shall implement the following measures:

• Occupied burrows shall not be disturbed during the nesting season (February 1 through August 31).

• If avoidance is the preferred method of dealing with potential effects, no disturbance shall occur 

within 160 feet of occupied burrows during the non-breeding season or within 250 feet during the 

breeding season.

• If destruction of occupied burrows is unavoidable during the non-nesting season (September 1–

January 31), passive relocation techniques (e.g., installing one-way doors at burrow entrances) shall 

be used instead of trapping and active relocation. At least one week will be necessary to accomplish 

passive relocation and allow owls to acclimate to alternate burrows. Unsuitable burrows that will 

not be destroyed in the vicinity of the Project shall be enhanced (enlarged or cleared of debris).

1 Wildlife Crossing Structure Handbook Design and Evaluation in North America: Chapter 4. Designs, Toolboxes, Guidelines, and 

Practical Applications. Prepared by Western Transportation Institute for Federal Highway Administration Planning. 224 pages. 

Available at: https://www.fhwa.dot.gov/clas/ctip/wildlife_crossing_structures/ch_4.aspx

2 Spencer, W.D., P. Beier, K. Penrod, K. Winters, C. Paulman, H. Rustigian-Romsos, J. Strittholt, M. Parisi, and A. Pettler. 2010. 

California Essential Habitat Connectivity Project: A Strategy for Conserving a Connected California. Prepared for California 

Department of Transportation, California Department of Fish and Game, and Federal Highways Administration. 3 California Department of Fish and Wildlife (CDFW). 2018. Areas of Conservation Emphasis (ACE) Version 3.0 Model. Website 

https://map.dfg.ca.gov/ace/