Mullan Road - Credit: Wikimedia Commons
Mullan Road - Credit: Wikimedia Commons
Mullan Road was the first wagon road to cross the Rocky Mountains to the Inland of the Pacific Northwest. It was built by U.S. Army troops under the command of Lt. John Mullan, between the spring of 1859 and summer 1860. It led from Fort Benton, which at the time was in the Dakota Territory, then Idaho Territory from July 1863, and into Montana Territory beginning in May 1864. The road eventually stretched all the way from Fort Walla Walla, Washington Territory, near the Columbia River to the navigational head of the Missouri River, which at the time was the farthest inland port in the world). The road previewed the route approximately followed by modern-day Interstate 15 and Interstate 90 through present-day Montana, Idaho, and Washington. Read more on Wikipedia
Source: en.wikipedia.org