East from Butte, Interstate 90 remains along the former U.S. 10 corridor to Whitehall, Three Forks and Bozeman. U.S. 191 joins the route between Bozeman and Big Timber and U.S. 89 for seven miles at Livingston. Continuing east along the Yellowstone River, Interstate 90 reaches Columbus, Laurel and Billings, where I-94 splits and follows old U.S. 10 to Miles City, Glendive and Bismark, North Dakota. Interstate 90 enters Montana's largest city with U.S. 212 and exits it with both U.S. 212 and U.S. 87 to Hardin and the Crow Indian Reservation.
Interstate 90 turns south from Hardin, remaining cosigned with U.S. 87 to Sheridan and Buffalo, Wyoming while U.S. 212 peels away from the freeway south of Crow Agency for Lame Deer and Broadus. I-90 concludes a 552.364 mile cross-state route south of Aberdeen through hilly grasslands.
Interstate 90 Montana Guides
Three sections of Interstate 90 were opened in October 1966. They included portions in Billings, Manhattan and Bozeman and between Butte and Whitehall. Opening of I-90 across Homestate Pass represented the second Interstate crossing of the Continental Divide in the U.S.1