What) The Salton Sea is a saline, endorheic rift lake located directly on the San Andreas Fault. The lake occupies the lowest elevations of the Salton Sink in the Colorado Desert of Riverside and Imperial Counties in Southern California. Like Death Valley, it is located below sea level, with the current surface of the Salton Sea at 226 ft (69 m) below sea level. The deepest area of the sea is 5 ft (1.5 m) higher than the lowest point of Death Valley. The lake covers a surface area of approximately 376 sq mi (970 km2) making it the largest in California. While it varies in dimensions and area with changes in agricultural runoff and rain, it averages 15 mi (24 km) by 35 mi (56 km), with a maximum depth of 52 ft.

    As a result, the Salton Sink or Salton Basin has had a long history of alternately being occupied by a fresh water lake and being a dry, empty desert basin, all according to random river flows, and the balance between inflow and evaporative loss. A lake would exist only when it was replenished by the river and rainfall, a cycle that repeated itself countless times over hundreds of thousands of years - most recently when the lake was recreated in 1905.  The creation of the Salton Sea of today started in 1905, when heavy rainfall and snow melt caused the Colorado River to swell, overrunning a set of head gates for the Alamo Canal. The resulting flood poured down the canal and breached an Imperial Valley dike, eroding two watercourses, the New River in the west, and the Alamo River in the east, each about 60 miles (97 km) long. These two newly created rivers carried the entire volume of the Colorado River into the Salton Sink, filling it in approximately two years. The Southern Pacific Railroad attempted to stop the flooding by dumping earth into the head gates area, but the effort was not fast enough, and as the river eroded deeper and deeper into the dry desert sand of the Imperial Valley, a massive waterfall was created that started to cut rapidly upstream along the main stem of the Colorado River. This waterfall was initially 15 feet (4.6 m) high but grew to a height of 30 feet (9.1 m) before the flow through the breach was finally stopped. It was originally feared that the waterfall would recede upstream into the Nevada-Arizona area, attaining a height of up to 100 to 300 feet (30 to 91 m), from where it would be even more difficult to fix the problem. As the basin filled, the town of Salton, a Southern Pacific Railroad siding and Torres-Martinez Indian land were submerged. The sudden influx of water and the lack of any drainage from the basin resulted in the formation of the Salton Sea. (1)

    Why) Pam found the above explanation quite interesting as it touches on her love of rivers, her desire to know how things came to be and her fascination with the behaviour of human beings.  We didn't spend any time at the lake but it made a nice scenic backdrop for our drive.