Mojave desert tortoise

Gopherus agassizii

Range, survey protocols, and qualification resources for biologists and project teams working in the desert.

Federal status: ThreatenedRange: parts of CA · NV · UT · AZTTB field support: California & Nevada

The Mojave population is federally listed and occurs north and west of the Colorado River. USFWS species overview

Where the Mojave population occurs.

The range spans southeastern California, southern Nevada, southwestern Utah, and northwestern Arizona. Use the map to orient your project, then review the site and the applicable agency guidance.

USFWS Mojave population screening range shaded in sage, with California, Nevada, Utah and Arizona borders, reference cities, a compass and distance scale. — **Read this as a broad screening map.** The USFWS mapped range can extend beyond occupied habitat. Shading does not establish tortoise presence, survey needs, or designated critical habitat for an individual property. On mobile, open the full-size map to zoom into labels.

Open full-size map Download printable map (PDF)Compare with the USFWS map

Range geometry: USFWS Mojave population range layer, retrieved September 14, 2026. State borders: U.S. Census Bureau, 2025. Original cartography by Travel Twist Biologist with Higgsfield illustration. For a habitat-potential view, see the USGS model reproduced in the 2019 USFWS protocol, Figure 1.

How do I use this for a real project?

Start with the work area, access routes, proposed activities, and schedule. Review existing surveys and project approvals, then confirm the appropriate survey approach with the responsible agency office. A location-based species list in USFWS IPaC can support that review.

Need to share the work area? Draw a project outline or map it with your phone.

Choose the guidance that fits the work.

Pre-project surveys, clearance work, and monitoring serve different purposes. Check the document date and the project’s written conditions before planning fieldwork.

Pre-project surveys

USFWS guidance for determining presence, estimating abundance when appropriate, and documenting habitat. Includes survey types, field methods, and reporting information.

USFWS · October 8, 2019

Open survey protocol

Field manual

Reference chapters on clearance surveys, handling, exclusion fencing, and biologist roles. Use this older manual with current agency guidance and project-specific conditions.

USFWS · December 2009 · PDF

Open field manual

Surveyor information

Find USFWS state contacts, surveyor resources, and training information. This is a useful starting point for confirming the current instructions for your work area.

USFWS · Live resource collection

Find guidance and contacts

A document or training certificate does not itself authorize handling, relocation, or other restricted work. The relevant authorizations and their conditions control the activities allowed.

Prepare your qualifications.

The USFWS Desert Tortoise Authorized Biologist Qualifications Form provides a structure for documenting education, training, relevant experience, and the project duties for which authorization is sought.

The verified source is Section 3.2 of the December 2009 field manual, starting on printed page 3-3 (PDF page 20). Confirm the current form and submission instructions with the responsible agency office.

Open USFWS qualification form Find the state contact

A long-lived desert specialist.

Built for shelter

Burrows help tortoises avoid harsh conditions. Time spent below ground makes survey timing and careful observation important.

More than sandy flats

Habitat includes alluvial fans, washes, canyons, and rocky foothills. Site conditions matter alongside the broad range map.

Slow to replace

Desert tortoises can live roughly 50–80 years and take about 13–20 years to reach sexual maturity. Habitat loss, roads, disease, and other pressures affect their recovery.

Biology and threats: USFWS species account. This page focuses on the Mojave population, not the Sonoran desert tortoise (Gopherus morafkai).

Tools for your tortoise fieldwork.

Find anatomy references, field guides, field tools, and qualification-form resources in the Biologist Tool Dashboard.

These resources support your work and do not replace project-specific training, agency instructions, or required authorizations.

Explore the dashboard.

Create a free account to access the anatomy tool and download the fillable qualifications form. Browse other individual tools and membership options.

Open the Tool Dashboard Explore digital tools

Reference links checked September 14, 2026. Agency guidance and project conditions can change; use the linked official sources when planning work.

See all consultant tools and resources