[2] The Little Salmon River rises at an elevation of 6,280 feet (1,915 m) above sea level on Blue Bunch Ridge in the Sawtooth Range of south-central Idaho, near Payette Lake.

[1][3] A U.S. Geological Survey stream gauge at the mouth recorded an average flow of 731.1 cubic feet per second (20.7 m3/s) from 1952 to present.

[5][6][7] The Little Salmon River formed as a result of a rift valley developing between the Rocky Mountains and the Columbia Plateau section of the Intermontane Plateaus.

Columbia River basalts underlie much of the western and central parts of the watershed, while other types of volcanic rock of closer origin form the foundations of the eastern mountains.

[3] The upper section of the watershed is a broad and low-gradient, sediment-floored valley used primarily for agriculture and ranching activities.

[citation needed] Historically, the Nez Perce, Shoshone, and Bannock Native American tribes inhabited the watershed of the Little Salmon River.

Their lifestyle depended on the river for salmon and on the surrounding lands for other animals, as well as precious natural minerals and resources that provided them with items to trade.

Europeans introduced horses to the Bannock, who in turn spread their use to the Shoshones, allowing them to travel further and hunt buffalo and other big game.