The West, North and East Forks of the San Gabriel River drain the largest watershed in southern California’s magnificent San Gabriel Mountains. The forks of the river provide thirsty urban residents with clean drinking water, as well as outstanding opportunities to swim, picnic, camp, fish, hike, and backpack in scenic river canyons.
An area of high ecological significance identified by the Forest Service, the forks are the best remaining habitat in southern California for the threatened Santa Ana sucker and other native fish. The upper East Fork also supports
Coastal rainbow trout and the endangered mountain yellow-legged frog.
A gold rush on the East Fork in 1854 led to the opening and exploration of the San Gabriel Mountains. Most of the mining camps were wiped out by floods in 1862.
According to the definitive guide Trails of the Angeles backpacking along the upper East Fork offers “monumental” scenery and “nature in its grandest proportions.” The popular Gabrieleno National Recreation Trail parallels much of the upper West Fork.