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 battle by the History Channel. The alternative name usage in the 1800s by the Sioux, Cheyenne and Crow of "Greasy Grass" for the "Little Bighorn" is reflected in current day nomenclature at the Little Bighorn battlefield. A prominent ridge on the Little Bighorn Battlefield that overlooks the eastern banks of the Little Bighorn River has retained the name of Greasy Grass Ridge, and is the site of critical events of the battle. In Lakota, the Little Bighorn River is called . Upstream from the point where the Little Bighorn issues from the Little Horn Canyon canyon, the stream flow is