Montana Highway 78 (MT 78) in the U.S. state of Montana is a state highway running in a northerly direction from an intersection with U.S. Highway 212 (US 212) at the city of Red Lodge.

It runs through Roscoe and Absarokee.

The highway extends about 49 miles (79 km) to a northern terminus at Interstate 90 (I-90) in the town of Columbus.

[2] Before receiving its present designation in 1978, MT 78 was designated as Montana Secondary Highway 307 (S-307).

[3][4] Media related to Montana Highway 78 at Wikimedia Commons