For thousands of years, the Aqui-dika, or Salmoneater people of the Shoshone, and other tribes crossed this pass on the Continental Divide, which the Shoshone called "Wee-yah-vee," using it as a natural passageway between the Salmon River valley to the west and Horse Prairie Creek to the east through the Bitterroot Range of the Rocky Mountains. Their trail guided Lewis and Clark in 1805, and in later years mountain men and fur traders called the route North Pass. The name Lemhi Pass dates to 1855, when Mormon pioneers established Fort Limhi in the valley west of here; the name came from a king in the Book of Mormon, was later respelled "Lemhi," and remained after the fort was abandoned in 1858, becoming associated with the land and the Lemhi Shoshone. Idaho's gold rush in the Leesburg district near Salmon City created demand for a road over the pass, and by the early 1880s freight wagons and stagecoaches were using it. The route stayed busy until 1910, when the Gilmore & Pittsburgh Railroad opened over Bannock Pass. Since the 1930s, the Civilian Conservation Corps, U.S. Forest Service, and local governments have relocated and improved sections of the old stage road, and although vegetation and newer roads now obscure the Indian trail Lewis and Clark followed, parts of the old stage road can still be traced on both sides of the pass. One of several lines on the route, the Red Rock-Salmon City Stage Company covered 68 miles between the Utah & Northern Railroad at Red Rock, Montana, and Salmon City, Idaho, ran eight stagecoaches daily, charged $8.00 for a one-way fare, and employed 14 Concord coaches, 12 freight wagons, 80 horses, and 35-40 people; in one banner year, it carried 3,000 passengers and 1,000,000 pounds of freight and U.S. mail over Lemhi Pass.