Sandwiched between two broad basins - Big Horn to the west and Powder River to the east - are the Big Horn Mountains. To the early explorers, this 70 mile long range was "The Shining Mountains," a name inspired by its snowcapped peaks, some topping 13,000 feet. The Indians called it Ahsahta, meaning "The Big Horns," after the Rocky Mountain bighorn sheep found here.

US 16 was the original "Black and Yellow Trail," first proposed in 1912 as a link between Chicago, the Black Hills, and Yellowstone. The first caravans of automobiles made it over the old sheepwagon tracks in the following year, reaching Yellowstone after 18 hard days on the road.