About Us

Sonny Bono Salton Sea National Wildlife Refuge

The Sonny Bono Salton Sea National Wildlife Refuge is located in California’s Imperial Valley, 40 miles north of the Mexican border, along the southern end of the Salton Sea. The refuge has two separate managed units, 18 miles apart, each one bordered by the Salton Sea on the north and by farmlands on the east, south, and west. Each unit contains wetland habitats, farm fields, and desert uplands. All the land that makes up the refuge is flat except for Rock Hill, a small, active volcano.

Because of its southern latitude, its location in the Sonoran Desert, and its elevation of 227 feet below sea level, the refuge sees some of the hottest temperatures in the nation. Daily temperatures from May to October exceed 100°F with temperatures of 116°-120°F recorded yearly. The Salton Sea Authority has measured the current salinity of the sea to be 60 PPT (parts per thousand); by comparison, ocean water is approximately 35 PPT. Despite the harsh environmental conditions, the Salton Sea supports one of the most diverse avian compositions in the United States as well as a host of endangered and other wildlife species.

The Salton Sea

Since its initial flooding in the 20th century, the Salton Sea has attracted a tremendous diversity of birdlife, drawn by the mix of saltwater and freshwater habitats, marshes, desert upland, and ryegrass fields. Migratory birds traveling along the Pacific Flyway have sought out this wetland oasis to refuel before continuing on their journey. Historically the sea has been a winter home for more than 90% of the western population of American White Pelicans and has hosted millions of eared grebes during their southward migration. On the refuge and in the immediate surrounding area, over 400 species of birds have been documented.

But over time, the Salton Sea has shrunk in size, in part because of the natural evaporation of water in the hot desert and reduced snow packs feeding the Colorado River and in part because of changing farming practices. As farm fields are fallowed to supply additional water to San Diego County, while others switch from flood irrigation practices to sprinkler irrigation. Combining all these factors with the fact that the sea has no outlet, it is no surprise to see that it has also grown saltier with each passing year. The sea is now almost twice as salty as the Pacific Ocean and has lost its ability to sustain the fish and organisms that are essential food for migrating birds except for where the agricultural water drains into the sea and the New and Alamo River Deltas. At a different time, other water bodies would have provided alternate spots for migrating birds. But with the loss and/or degradation of other suitable wetland habitats along the Pacific Flyway, all ongoing conservation work is essential to keep the Sea as a vital stopover site along the flyway. 

Our Mission


Sonny Bono Salton Sea National Wildlife Refuge is managed under the LEA Act: to create and maintain wildlife habitat to reduce crop damage to the surrounding agriculture and protect migratory birds and threatened and endangered species, to provide opportunities for wildlife-oriented recreation and study and conserve the Salton Sea.

The refuge actively managed over 3000 acres of land for migratory bird's use. Of those 3000 acres, refuge staff farm and irrigate over 2000 acres for ryegrass, wheat, and seasonal duck ponds during the summer months to provide vital nutrients for our wintering birds. Most of our ponds and fields are managed using fresh water purchased through Imperial Irrigation District while some ponds get a mixture of freshwater and drainage water from neighboring farms to help with water conservation efforts. 

  • In 1930, 32,766 acres were set aside to establish the Salton Sea Refuge. At 37,900 acres today, the refuge is designated as an Important Bird Area by the American Bird Conservancy and a Regional Shorebird Reserve by the Western Hemisphere Shorebird Reserve Network.

Our History

Ancient Lake Cahuilla

The Salton Sea is the most recent form of Lake Cahuilla, an ancient lake that has cyclically formed and dried over the millennia due to natural flooding from the Colorado River. The first iteration of Lake Cahuilla was formed when sediments from the Colorado River Delta closed off the gulf of California and created the Salton Sea trough. Over time seismic activity, glaciation, and the fluctuation of the Colorado River have changed the size, shape, and salinity of the Sea. At its largest iteration, the Sea was 300 ft deep, 35 miles wide, and 100 miles long roughly covering all the land between El Centro or Calexico (according to some historic accounts) to Indio California. The Sea is the traditional and ancestral lands of the Cahuilla peoples of the Cahuilla nation at the north end and the Kumeyaay tribe to the south.

The Current Sea

The current Salton Sea was formed when the Colorado River floodwater breached an irrigation canal near Yuma, Arizona in 1905 and flowed into the Salton Sink. Remnants of this flood can be seen along the banks of the New River. For more than a century, the sea was sustained by water from irrigation runoff and the New, Alamo, and Whitewater Rivers. This sea in the desert became a favorite getaway for Hollywood stars and was stocked with sport fish to entice anglers. As water consumption increased in the major cities within southern California less and less water was allotted for the sea cumulating to the current shrinkage. If no conservation effort is taken, the sea is expected to shrink even more, until it is roughly 1/10th of its current size.

Other Facilities in this Complex

The Sonny Bono Salton Sea National Wildlife Refuge is managed as part of the Sonny Bono Salton Sea National Wildlife Refuge Complex. A National Wildlife Refuge Complex is an administrative grouping of two or more refuges, wildlife management areas or other refuge conservation areas that are primarily managed from a central office location.  

The other refuge in the Sonny Bono Salton Sea National Wildlife Refuge Complex includes:
  • Sonny Bono Salton Sea National Wildlife Refuge and The Refuge Complex headquarters:
    • 906 West Sinclair Road, Calipatria, CA 92233. 
  • Coachella Valley National Wildlife Refuge: Preserve. This refuge does not have a visitor center and is closed of to the public. Visitors can drive up to the 1000 Palm Oasis Preserve to learn more about the Refuge and the Coachella Valley Preserve that the refuge is a part of. Please visit the 1000 palms website for more information, including hours of operation.