El Mirage Lake, located in the central Mojave Desert within San Bernardino County, California, is widely recognized as a dry lakebed. This geological feature, approximately 6 miles long and at an elevation of about 2,840 feet, presents a unique landscape. Its flat, expansive surface has drawn attention for various activities, prompting inquiries about its historical drying.
Understanding El Mirage’s Water Cycles
El Mirage Lake is not a body of water that dried up at a single point in time; instead, it is an ephemeral lake, also known as a playa. This means the lake naturally alternates between periods of being wet and dry, a characteristic driven by the region’s limited and infrequent rainfall and the high rates of evaporation. The lakebed forms in an undrained basin, where water collects without an outlet.
During rainfall events, which typically average between 4 to 6 inches annually, water flows into the basin, primarily as surface runoff from the San Gabriel Mountains via Sheep Creek. This inflow deposits silt and clay, which then settle on the lakebed. When the water evaporates under the desert’s hot, dry climate, it leaves behind a hard, smooth clay surface that defines the dry lakebed.
Documented Periods of Dryness
El Mirage Lake’s intermittent nature has been observed for an extended period, with its dry state becoming particularly significant for human activities in the 20th century. The flat, hard surface of the lakebed naturally attracted early automobile enthusiasts. By the 1920s, people began using the dry lakebed for racing.
The Southern California Timing Association (SCTA) was established in 1937 to bring organization and safety to these racing endeavors. The SCTA conducted its first organized event at El Mirage in 1938, marking the formal beginning of land speed racing on the lakebed. This activity continued consistently from that time, pausing only during World War II, when the U.S. military utilized El Mirage as an airfield for training purposes.
The Modern El Mirage Lakebed
Today, El Mirage Lakebed remains a widely used and recognized site, primarily serving as a popular location for various recreational activities. It is a key part of the El Mirage Off-Highway Vehicle (OHV) Recreation Area, managed by the Bureau of Land Management (BLM). The area encompasses approximately 27,275 acres, with the lakebed itself spanning about 4,800 acres.
Visitors engage in activities such as land speed racing, off-roading with motorcycles and ATVs, and even ultralight aircraft operations. To maintain the integrity of the lakebed’s surface, it is subject to closures when wet or muddy. Entry to the recreation area requires a pass, with options for daily, weekly, or annual permits. Additionally, El Mirage is a frequent backdrop for commercial filming, appearing in various advertisements and movies.