U. S. Highway 89
North leg: Piegan, Montana – Yellowstone National Park, Wyoming
Mileage: 404 Miles
South leg: Yellowstone National Park, Wyoming – Flagstaff, Arizona
Longest Mileage: 1281, Current Mileage: 848 Miles
U.S. 89 is a 1934 highway. The original southern terminus was Nogales, Arizona. Its current north to south route stops at Yellowstone and picks up again south of the park. The current route travels through 5 states.