
The 9,000-acre Sweeney Granite Mountains Desert Research Center borders the 1.8 million-acre Mojave National Preserve. The reserve encompasses the 2070 m (6,796 ft.) summit of the rugged Granite Mountains. High plateaus and ridges dominated by piñon-juniper woodland and sagebrush descend precipitously to the east in highly fractured granitic canyons. Massive pinnacles and broken, rocky terrain eventually give way to densely vegetated bajadas and washes, supporting creosote bush scrub, a unique community of enriched mixed woody and succulent scrub, and other habitat types.
Variation in habitat, hydrology, and elevation supports widely diverse plant and animal life, including nearly 500 native species of vascular plants, one amphibian, 34 reptiles, 159 birds, and 45 mammals. Nearly 40% of the biodiversity is associated with the abundant springs and seeps located throughout the range. The reserve also protects a dense concentration of archeological and historical sites.
Sweeney Granite Mountains Desert Research Center administers two satellite reserves. The Sacramento Mountains Reserve lies on the steep slopes and flat bajadas of the Sacramento Mountains in California’s eastern Mojave Desert, 24 km (15 mi.) west of the Colorado River. This site supports plant species allied to the Sonoran Desert, such as a large stand of Bigelow’s teddy bear cholla (Cylindropuntia bigelovii) and one of the northernmost occurrences of ocotillo (Fouquieria splendens). The Old Woman Mountains satellite reserve is also located in a transitional bioregion between the Mojave and Sonoran Deserts roughly 80 km (50 mi.) southeast of the Granite Mountains. The Old Woman Mountains reach 1,623 m (5,325 ft.) in elevation and host a rich mosaic of vegetation, including stands of pinyon-juniper, Mojave yucca, nolina, and blackbrush. Both satellite reserves are surrounded by public lands administered by the U.S. Bureau of Land Management.
Teaching and Field Courses
Many universities and institutions utilize the reserve to teach field courses and workshops in a variety of disciplines, such as geology, ecology, botany, and zoology. Interpretive loop trails and 22.5 km (14 mi.) of backcountry trails provide access to the outdoor classroom experience.
Public Outreach
The reserve offers guided tours and field trips for public and non-profit groups, workshops and conferences, and offers volunteer opportunities. Science Newsletter, published by the reserve, represents a collaborative effort with Mojave National Preserve to highlight research being conducted in the area with the goal of informing local land managers, the academic community, and the general public. The reserve plays a critical role in the region by collaborating with government agencies on biodiversity inventories, land management, and conservation issues.
Selected Research
- Linkages between biotic and physical components of piedmont landscapes.
- Characterization of microbial communities and desert soil crusts.
- Evolution of desert adaptations and response to environmental changes.
- Plant-pollinator interactions and multiple trophic level community ecology.
- Ecology and systematics of ants, wasps, and bees.
- Lizard ecology, locomotion, and habitat use.
- Bighorn sheep demographics and dietary requirements.
- Rattlesnake life history/ distributional ecology.
- Kangaroo rat physiology and foraging behavior.
- Regional tectonics and seismology.
- Long-term demographics of desert shrubs.

