Flowing into the heart of the Mojave Desert, the Mojave River exists mostly underground. Surface channels are usually dry absent occasional groundwater surfacing and flooding from extreme weather events like El Niño. 

River Course

Pushing northward from the rugged San Bernardino Mountains, the river runs into the Soda Dry Lake in the middle of the Mojave Desert. Its waters are mostly from the snowmelt from the 40 inches of annual precipitation falling onto the peaks of the San Bernardino Mountains – ultimately providing an average of 50,000 acre-feet of water per year – and the State Water Project. The State Water Project’s Southern California region provides up to 85,800 acre-feet of water to the Mojave Basin, pumping water along the East Branch into Silverwood Lake and further along the California Aqueduct to be distributed via recharge stations along the river from Hesperia to Daggett. From headwaters to terminus, the Mojave River crosses a linear distance of about 110 miles. 

History

U.S. government explorer John C. Frémont found the river in 1844 thanks to the Mojave Indians, and in turn named it after them. Like much of the rest of California, mines were established in the Mojave during the California Gold Rush. Silver and iron ore were particularly abundant metals found in the desert, the latter of which was excavated for the building of the Liberty ships during World War II. 

Adjudication

The Mojave Watershed was adjudicated in 1996 in an effort to preserve the limited resources typical of arid regions by regulating groundwater allocations. Surface and groundwater in the watershed are closely connected; the Mojave River recharges the two aquifers that are hydraulically linked to one another. The adjudication was initiated by a 1990 lawsuit filed by the City of Barstow and Southern California Water Company, claiming excessive water use in the upper Mojave River Basin, thus reducing the amount of surface and groundwater available to the central Basin. Additional cross-complaints were filed and several parties joined the lawsuit.

For more than 18 months, water producers of all types who were reliant 
upon the Mojave River Basin commenced negotiations which eventually 
produced the “Final Judgment” on how the groundwater supply could be 
fairly distributed. The Mojave Basin was the 12th to be adjudicated in the state of California.