100 years of US routes: 1926-2026
This page is about the north segment of US 191 (not to be confused with the separate south segment of US 191). In 1962 (back when US 191 was still a single, continuous route), the north end of US 191 was extended to Malta MT. That is where the north terminus was still located in 1981, when a big change was approved for US 191: the route was extended south to Chambers AZ (via what had been US 187 through Wyoming). In order to get there, US 191 was assumed to follow an implied route through Yellowstone National Park. However, since US routes do not exist in Yellowstone, this action created two separate, disconnected segments of US 191.
1926-1981
Originally US 191 was not a split route; see this page
1981-1997
North: Malta, MT
South: West Yellowstone, MT
1997-present
North: Morgan, MT
South: West Yellowstone, MT
Our 2020 measurement yielded 437.4 miles for the north segment of US 191. 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).
The southern terminus of US 191's north segment has always been at West Yellowstone.
In 1997 US 191 was extended north from Malta to the Port of Morgan, on the Canada border. This photo was looking north at the border, at the end of US 191:
On the left side of the road is the US customs office. The green sign instructs people leaving the USA to report to the Canadian customs office, which is the building in the distance on the right side, shown close-up here:
"Monchy" is the name for the Canada side of this port; that is Saskatchewan highway 4 continuing ahead. Since those photos, the American station has been replaced:
Research and/or image credits: Julian Macdonald; Dale Sanderson; Michael Summa