In 1905, the Colorado River burst through an irrigation canal and flooded California's Salton Sink for 18 months straight, accidentally creating the state's largest lake - now a toxic, shrinking environmental catastrophe.
An Unintentional Ocean
In the autumn of 1904, engineers from the California Development Company made a fateful decision. To increase water flow for Imperial Valley farms, they cut an opening in the western levee of the Colorado River. Lacking control gates, this breach became uncontrollable when massive floods hit in early 1905. For the next 18 months, the entire volume of the Colorado River poured into the Salton Sink, a desert basin with a bottom elevation of -278 feet below sea level. By the time the breach was sealed in February 1907, a 378-square-mile lake had formed—the Salton Sea.
This new inland sea, located in a basin that was once part of the ancient Lake Cahuilla, quickly became a mid-century resort destination. Developers built towns like Salton City and Bombay Beach. The California Department of Fish and Game introduced several species of saltwater fish, including orange-mouth corvina and sargo, to create a sport fishing paradise. For a time, the Salton Sea State Recreation Area drew more annual visitors than Yosemite National Park. But the sea's fundamental geology—it is a terminal lake with no outlet—doomed this accidental oasis from the start.
The Slow Collapse
With no outflow, water in the Salton Sea leaves only through evaporation. This process relentlessly concentrates the salts and chemicals that flow in from agricultural runoff. Each year, about 4 million tons of dissolved salts are deposited in the lake. Its salinity, once similar to the ocean at 35 grams per liter, now exceeds 55 g/L, making it over 50% saltier than the Pacific.
The agricultural runoff, high in nitrates and phosphates, also fuels massive algae blooms. When these blooms die, their decomposition by bacteria consumes the water's oxygen, creating vast anoxic zones. These events trigger enormous die-offs. Millions of tilapia, one of the few fish species that can still tolerate the high salinity, have been known to perish in a single day. This, in turn, affects the avian populations. The sea is a stop on the Pacific Flyway for over 400 bird species. Large-scale deaths of eared grebes and American white pelicans have been linked to avian botulism and other diseases that thrive in the stressed ecosystem.
As the lake shrinks, it exposes the contaminated lakebed, or playa. This dry surface is laden with fine particles of salt, pesticides, arsenic, and selenium from decades of agricultural drainage. Strong desert winds pick up this dust, carrying it for over 100 miles and creating a public health crisis for local communities, with studies showing links to increased rates of asthma and reduced lung function in children.
💡Fun Facts
The beaches are not made of sand. They are composed almost entirely of the pulverized bones and spines of billions of dead fish and barnacles.
The area produces geothermal energy. The Salton Sea Geothermal Field has a potential generating capacity of 2,950 megawatts.
The deep geothermal brines are also one of the world's most promising sources of lithium, a critical component for rechargeable batteries.
Despite its toxicity, the sea is habitat. About 90% of the entire population of eared grebes and 50% of the ruddy ducks on the Pacific Flyway use the sea during migration.
The Salton Sea State Recreation Area day use and campground are open 24 hours. The Visitor Center is typically open from 10 a.m. to 4 p.m., but days vary by season.
Admission
Day use vehicle entry is $7.
Accessibility
The terrain around the Visitor Center and some campsites is accessible, but the shoreline is uneven and soft. No designated accessible fishing facilities exist, but many fish from the Varner Harbor picnic area.