San Joaquin River

The San Joaquin River, the second longest river in California, originates from the western slopes of the Sierra Nevada and is tributary to the Tuolumne River, Stanislaus River, Merced River, Calaveras River and Mokelumne River.

The basin covers about 38,000 square miles, or one-fifth of California, being the same size as the state of Indiana. Having three forks, the river originates from three different locations. The South Fork begins at Martha Lake, the Middle Fork eat ast of Junction Butte while the at 3410 m elevation, here being an unnamed lake.

San Joaquin has been developed for human use beginning with the 19th century.  The hydroelectricity produced here is exported to the Bay Area, the water is used for irrigation, while also being the source of drinking water for several regions in California's central valley. One million acres are irrigated, producing $2 billion in crops every year.

The river supported the highest salmon run in North America. After the human developments, the California Department of Fish and Game announced in in 1928 that very few salmons remained in this area.