Sonny Bono Salton Sea National Wildlife Refuge

Sonny Bono Salton Sea National Wildlife Refuge

906 W. Sinclair Road
Calipatria, CA 92233

The refuge was established in 1930 by President Herbert Hoovers's Presidential Proclamation. It is located along the course of the Pacific Flyway in the Imperial Valley California. Originally the refuge consisted of 37,600 acres. Now, because of flooding by the Salton Sea, only about 2,200 manageable acres remain. Dikes are expected to keep the Sea from further encroachment on the refuge.

From gulf to ancient sea to desert

At one time the Gulf of California extended into what is now known as the Imperial and Coachella valleys. A natural dam was then formed through silt deposits off the Gulf and resulted in the formation of an ancient sea. Through time, the Sea evaporated and formed a dry alkaline basin. In the early 1900s only dry desert shrubs were present where the refuge and lakeshore is today.

Sea recreated in 1905 from break in irrigation canal

In 1901, Colorado River waters were diverted from Yuma, Arizona, into Mexico and back into the Salton Sea basin for agricultural development. in 1905, failure of a diversion structure caused the Colorado to flow unchecked into the Imperial Valley between 1905 and 1907, thus creating the present Salton Sea. Agricultural drainage and runoff from the surrounding mountains now supply the Salton Sea. There is no outlet from the Sea, and water is removed only by evaporation.

Over 200 feet below sea level

The Salton Sea covers 380 square miles. Its width varies from 9 to 15 miles, it is 35 miles long with about 115 miles of shoreline. The depth of the Salton Sea varies with the gentle valley slope to a maximum of about 51 feet. The surface elevation is currently about 227 feet below sea level.

Waterfowl have adapted to changing habits and foods in Imperial and Mexicali Valleys

Before the Salton Sea was formed waterfowl were only found along the marshes and delta of the Colorado River (primarily in Mexico). During the 1920s, as more water was diverted from the Colorado River for agriculture, marshes were inadvertently created. These marshes, at the edges of the then smaller Salton Sea, resulted from agricultural water runoff. Waterfowl were attracted to the marshes from their former winter home in the drying Colorado River delta. As farming intensified in the 1940s and the Salton Sea expanded, marshland once again shrunk and waterfowl turned to the farmers's crops for food. Today, crops are grown on the refuge to feed wintering waterfowl and to keep the birds from eating other crops in the area.

Numerous wildlife now conserved on the refuge

Thousands of waterfowl and other birds spend the winter on the refuge. Canada geese, snow geese, American avocets, black-necked stilts, pintails, green-winged teal, eared gebes, and a wide variety of other species are commonly seen during the winter.

The primary purpose of the refuge is to provide habitat for migrating and wintering waterfowl and endangered species. The refuge is also important in providing feeding, resting, and nesting habitat for a large number of shorebirds and in supporting a diversity of wildlife throughout the year.
Endangered Species at the refuge

The Yuma clapper rail breeds in the marshes along the Colorado River from the Nevada/California border south to the Colorado Delta region of Mexico. It is also found in marsh habitat around the south-eastern portion of the Salton Sea. The preferred habitat is mature cattail-bulrush stands in shallow fresh water. Yuma clapper rails occur in suitable habitat throughout the year and breed successfully on the refuge.

Other threatened or endangered species occasionally observed on the refuge include the bald eagle, California brown pelican, and desert pupfish.