Bighorn Mountains

The Bighorn Mountains are a mountain range in northern Wyoming and southern Montana in the United States, forming a northwest-trending spur from the Rocky Mountains extending approximately 200 mi northward on the Great Plains. They are separated from the Absaroka Range, which lie on the main branch of the Rockies to the west, by the Bighorn Basin. Much of the land is contained within the Bighorn National Forest.

Source: Wikipedia