Bighorn River Wind River Canyon near the town of Thermopolis. From there, the river flows through the Bighorn Basin in north central Wyoming, passing through Thermopolis and Hot Springs State Park. At the border with Montana, the river turns northeast, and flows past the north end of the Bighorn Mountains, through the Crow Indian Reservation, where the Yellowtail Dam forms the Bighorn Lake reservoir. The reservoir and the surrounding canyon are part of the Bighorn Canyon National Recreation Area. The Little Bighorn River joins the Bighorn near the town of Hardin, Montana. Approximately fifty miles farther downriver, the Bighorn River ends where
Little Bighorn River turn, would wet moccasins and leggings of Indian people, and the bellies and legs of horses, and cause them to look greasy. On the main stream, the name Greasy Grass slowly gave way to the name Little Bighorn. For one major tributary of the Little Bighorn, the (presently named) Lodge Grass Creek retained the name "Greasy Grass Creek", but as Joe Medicine Crow explained in the 2012 video, this name morphed from "Greasy Grass" to "Lodge Grass" due to the error of an interpreter since the Crow word for "greasy" is Tah-shay, and the Crow word for "lodge" is Ah-shay.