Highway 59 in the U.S. state of Montana is a route running northerly from the Wyoming state line to an intersection with Highway 200 near the south end of the town of Jordan, a distance of approximately 194 miles (312 km). At the Wyoming state line, the road becomes Wyoming Highway 59, which continues south 57 miles (92 km) to the city of Gillette. The landscape traversed by Highway 59 is mostly hilly and arid, largely used for open-range grazing; the only major commercial areas are the towns of Broadus and Miles City.
Highway 59 continues as Fence Creek Road from the Wyoming state line across the desert for several miles before running concurrently with US 212 north. The highway enters the town of Broadus as Park Avenue heading north, and turns onto Holt Street, leaving town headed west. Passing by the Broadus Airport and the Rolling Hills Golf Course, Highway 59 splits off from US 212 and continues northwest and then north through Olive and through meadows. Several miles later, Highway 59 passes through Volborg before entering Miles City and intersecting Interstate 94 (I-94) on Haynes Avenue. The route turns west on Main Street, briefly running concurrently with BL I-94 before turning northwest on North 7th Street and crossing the Yellowstone River. Highway 59 intersects Montana Secondary Highway 489 across from the Miles City Municipal Airport before continuing through the plains of eastern Montana. The road passes through Angela and Cohagen before ending at Highway 200 in Jordan.
The current Highway 59 is an amalgam of three roadway segments that were each formerly numbered separately. The highway south of Broadus was originally designated as Montana Secondary Highway 319. From Broadus to Miles City, the highway was U.S. Route 312 (US 312) until 1981, and Highway 59 north of Miles City was originally Highway 22. Although US 312 continued west from Miles City to Billings, this was a concurrency with US 10, and only the part between Miles City and Broadus was independent. However, from 1959 to 1962, US 312 extended west to Yellowstone National Park, and its east end was at US 12 in Forsyth. In 1962, US 212, which had ended in Miles City, was rerouted to absorb former US 312 southwest of Billings, and US 312 was extended southeast to Broadus over former US 212.