The Coachella Valley is a desert valley in Southern California which extends for approximately 45 mi (72 km) in Riverside County southeast from the San Bernardino Mountains to the northern shore of the Salton Sea. It is the northernmost extent of the vast trough which includes the Salton Sea, the Imperial Valley and the Gulf of California. It is approximately 15 mi (24 km) wide along most of its length, bounded on the west by the San Jacinto Mountains and the Santa Rosa Mountains and on the north and east by the Little San Bernardino Mountains. The San Andreas Fault crosses the valley from the Chocolate Mountains in the southeast corner and along the centerline of the Little San Bernardinos. The fault is easily visible along its northern length as a strip of greenery against an otherwise bare mountain.
The Chocolate Mountains are home to a United States Navy live gunnery range and are mostly off-limits to the public. In comparison to the "Inland Empire (IE)" (Riverside-San Bernardino area and the California desert), the Coachella Valley is referred to as the "Desert Empire" to differentiate it from the neighboring urbanized Inland Empire and the Imperial Valley. Geographers and geologists sometimes call the area, along with the Imperial Valley to the south, the "Cahuilla Basin" or the "Salton Trough".
The valley connects with the Greater Los Angeles area to the west via the San Gorgonio Pass, a major transportation corridor that includes Interstate 10 and the Union Pacific Railroad.
The valley is sometimes included as part of the 13th-largest metropolitan area in the United States, the Inland Empire metropolitan area.The famous desert resort cities of Palm Springs and Palm Desert lie in the Coachella Valley. There is a large population of seasonal residents in the winter months, known as snowbirds, which at peak times may surpass 100,000 with another 3.5 million annual conventioneers and tourists.
The local population rounds up to almost 500,000 in April, declines to 200,000 in July and rises to near 800,000 by January.