Endpoints of
US Route 89[n]

Mileage: in 1989 AASHTO listed a figure of 404 miles for the north segment of US 89.  Our own 2020 measurement yielded 399.7 miles.  Want historic mileages?  Our handy reference book includes the mileages that were published in all 13 of AASHO/AASHTO's historic route logs (spanning the years 1927 to 1989).

In 1934 the north segment of US 89 was commissioned.  Ever since, its north terminus has been on the Canada border in Montana, at a port of entry called Piegan.  The south end is in Gardiner MT, at the north entrance to Yellowstone National Park.  (US 89 does not exist within Yellowstone National Park, and although the route is implied to run through Yellowstone, the Park divides US 89 into two separate segments.) 

Research and/or image credits: Dale Sanderson; Michael Summa