river in Wyoming, U.S., formed by North and South forks in the Absaroka Range in Yellowstone National Park. It flows northeast past Cody and Lovell, joining the Bighorn River (Bighorn Canyon National Recreation Area) at Kane, near the Montana border, after a course of 100 miles (160 km). Buffalo Bill Dam and the Shoshone reservoir, which it impounds near Cody, are part of a power and irrigation project at the eastern end of Shoshone Canyon. The river was named for the Shoshone Indians.