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Southwest Region

The Southwest Region covers Arizona, California, Nevada, and a portion of southern Oregon. Our scientists do a broad array of research and technical assistance throughout the U.S. and across the globe. The Regional Office, headquartered in Sacramento, provides Center oversight & support, facilitates internal & external collaborations, and works to further USGS strategic science direction.

News

2025 in Review: The Saline Lake Ecosystems Integrated Water Availability Assessment

2025 in Review: The Saline Lake Ecosystems Integrated Water Availability Assessment

AquaDePTH: Merging Aquatic Disease Surveillance Data into One Useful Tool

AquaDePTH: Merging Aquatic Disease Surveillance Data into One Useful Tool

RAMPS Newsletter - Fall 2025

RAMPS Newsletter - Fall 2025

Publications

Imperiled Great Basin terminal lakes: Synthesizing ecological and hydrological science gaps and research needs for waterbird conservation Imperiled Great Basin terminal lakes: Synthesizing ecological and hydrological science gaps and research needs for waterbird conservation

Terminal lakes are declining globally because of human water demands, drought, and climate change. Through literature synthesis and feedback from the resource and conservation community, we review the state of research for terminal lakes in the Great Basin of the United States, which support millions of waterbirds annually, to prioritize ecological and hydrologic information needs. From...
Authors
Garth Herring, Ashley L. Whipple, Cameron L. Aldridge, Bryce Alan Pulver, Collin A. Eagles-Smith, Rich D. Inman, Elliott Matchett, Adrian P. Monroe, Elizabeth Kari Orning, Benjamin Seward Robb, Jessica E. Shyvers, Bryan C. Tarbox, Nathan D. Van Schmidt, Cassandra Smith, Matthew J. Holloran, Cory T. Overton, David O’Leary, Michael L. Casazza, Rebecca J. Frus

Bees of the Buenos Aires National Wildlife Refuge—A preliminary report on a bee survey in a vulnerable semi-desert grassland of the Sonoran Desert Bees of the Buenos Aires National Wildlife Refuge—A preliminary report on a bee survey in a vulnerable semi-desert grassland of the Sonoran Desert

Pollinators are vital to the continued existence and seed production of about 87.5 percent of all flowering plants (Ollerton and others, 2011). In the semi-desert grasslands of Buenos Aires National Wildlife Refuge, in the Sonoran Desert of the United States, flowering forbs provide seed vital to the food base of wildlife, including the 136 species of resident and migratory birds using...
Authors
Kathryn A. Thomas, Angela M. Hoover, M. Kathryn Busby

Analyzing spatial distributions and alignments of pitted cone features in Utopia Planitia on Mars Analyzing spatial distributions and alignments of pitted cone features in Utopia Planitia on Mars

Martian geomorphology and surface features provide links to understanding past geologic processes such as fluid movement, local and regional tectonics, and feature formation mechanisms. Pitted cones are common features in the northern plains basins of Mars. They have been proposed to have formed from upwelling volatile-rich fluids, such as magma or water-sediment slurries. In this study...
Authors
Mackenzie M. Mills, Alfred S. McEwen, Amanda N. Hughes, Ji-Eun Kim, Chris Okubo

Science

USGS Sagebrush Science: Supporting Public Safety and Economic Decision Making Across the West

The sagebrush biome is one of the largest ecosystems in North America. Encompassing nearly one-third of the continental U.S., it provides critical resources for millions of Americans and a home for hundreds of plants and animal species in the West. Natural resource management in sagebrush ecosystems can be complex, and science can support management decisions by providing knowledge and tools to...
USGS Sagebrush Science: Supporting Public Safety and Economic Decision Making Across the West

USGS Sagebrush Science: Supporting Public Safety and Economic Decision Making Across the West

The sagebrush biome is one of the largest ecosystems in North America. Encompassing nearly one-third of the continental U.S., it provides critical resources for millions of Americans and a home for hundreds of plants and animal species in the West. Natural resource management in sagebrush ecosystems can be complex, and science can support management decisions by providing knowledge and tools to...
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Tackling avian influenza with automated detection for an early warning system

The USGS is collaborating with agricultural and wildlife management partners to address the threat of highly-pathogenic avian influenza (HPAI) to wildlife, domestic poultry, and livestock. Partners include federal (U.S. Fish and Wildlife Service and U.S. Department of Agriculture) and non-federal agencies as well as State government, private organizations, and academic institutions. Our...
Tackling avian influenza with automated detection for an early warning system

Tackling avian influenza with automated detection for an early warning system

The USGS is collaborating with agricultural and wildlife management partners to address the threat of highly-pathogenic avian influenza (HPAI) to wildlife, domestic poultry, and livestock. Partners include federal (U.S. Fish and Wildlife Service and U.S. Department of Agriculture) and non-federal agencies as well as State government, private organizations, and academic institutions. Our...
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Drought versus Aridification in the Colorado River Basin

The Colorado River Basin is no stranger to drought. However, not all droughts are the same. Drought refers to a temporary state where conditions eventually return to normal. Aridification is the transition to persistent above-average dry conditions that do not return to normal. It is important to know whether the current, prolonged millennium drought (2000-present) is actually the first stages of...
Drought versus Aridification in the Colorado River Basin

Drought versus Aridification in the Colorado River Basin

The Colorado River Basin is no stranger to drought. However, not all droughts are the same. Drought refers to a temporary state where conditions eventually return to normal. Aridification is the transition to persistent above-average dry conditions that do not return to normal. It is important to know whether the current, prolonged millennium drought (2000-present) is actually the first stages of...
Learn More
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