North Fork American River
The North Fork American River is the longest branch of the American River in Northern California. It is long from its source at the crest of the Sierra Nevada, near Lake Tahoe, to its mouth at Folsom Lake northeast of Sacramento. Prior to the construction of Folsom Dam the river was about longer making for a total length of .
Middle Fork American River
The main stem of the river begins along the Sierra Crest, on the south flank of Granite Chief near Squaw Valley Ski Resort west of Lake Tahoe. It flows west then southwest into French Meadows Reservoir, which is impounded by the L.L. Anderson Dam. Below the dam the Middle Fork enters a rugged and inaccessible canyon more than deep. About downstream, the Middle Fork flows into the Ralston Afterbay, where it is joined from the east by the Rubicon River. Directly below this point, the North Fork of the Middle Fork American River joins from the north. The Middle Fork then flows southwest, past Foresthill, through the Auburn State Recreation Area, and into the North Fork directly below the Foresthill Bridge and above Highway 193. Below this confluence the North Fork flows a further to the Folsom Lake reservoir above Sacramento. Although nominally a tributary of the North Fork, the Middle Fork has a greater flow and drains a much larger watershed of .