What mountain range was crossed by the wagon road that connected Fort Walla Walla to the fort established in 1846 in Montana?
Mullan Road: Mullan Road was the first wagon road to cross the Rocky Mountains to the Inland of the Pacific Northwest. Mullan Road:  It led from Fort Benton, which at the time was in the Dakota Territory, then Idaho Territory from July 1863, and Montana Territory beginning in May 1864, and the navigational head of the Missouri River (and once farthest inland port in the world). Fort Benton, Montana:  Established in 1846, a full generation before the U.S. Civil War, Fort Benton is one of the oldest settlements in the American West; in contrast, many other places—including large cities today—were settled in the late 1860s, 1870s, or 1880s.
i don't know