Its headwaters are in the Absaroka Range in Shoshone National Forest.

It ends when it runs into the Big Horn River near Lovell, Wyoming.

Near Cody, it runs through a volcanically active region of fumaroles known as Colter's Hell.

[2] West of Cody the river is impounded in Shoshone Canyon by the Buffalo Bill Dam, created as part of the Shoshone project; one of the nation's first water conservation projects.

[3] Upstream of Buffalo Bill Reservoir the Shoshone splits into the North Fork, which follows a long canyon down from the Absaroka Mountains to the vicinity of the east entrance of Yellowstone National Park, and the South Fork, which originates at the southern end of the Absarokas.