Montana Road Network

By | October 13, 2022

Montana’s road network.

Montana has a thin road network. Many secondary roads are unpaved. Besides the Interstate Highways, there are hardly any 2×2 divided highways in Montana, as opposed to states further east. The distances in Montana are enormous, the longest distance that can be covered on a highway is 1,135 kilometers. Especially in the mountain areas and in the east, medical assistance can take a long time after accidents. There is certainly no traffic on the road network of Montana. Driving conditions can be harsh in winter and even life-threatening during snow storms and extreme cold. It is a good idea to take extra warm blankets, fuel and provisions with you on long journeys in the winter. What is special is that the border between Montana and South Dakota cannot be crossed via a paved road, this is the only situation in the United States where this is the case.

  • Bittranslators: State overview of Montana, including geography, economy, population and history as well as introduction to major cities of Montana.

Road management

The state highway authority is the Montana Department of Transportation, abbreviated MDT. The MDT operates 2,508 bridges, 20,829 kilometers of road, including 1,918 kilometers of Interstate Highway, 4,811 kilometers of non-Interstate Highways under the National Highway System (mainly US Highways), 4,143 kilometers of primary state highways, 7,401 kilometers of secondary state highways and another 2,555 kilometers of road that are not a numbered state highway, but are under state control.

The Montana Department of Transportation has its origins in the Montana Highway Department, which in turn has its origins in the State Highway Commission established in 1903. In 1915 this was expanded with a Bridge Department. The actual Montana Highway Department was formed in 1919. In 1992 the name was changed to the current Department of Transportation.

  • Deluxesurveillance: Nickname of Montana as The Treasure State. Also covers geography, history, economy, politics and administration of the state.

Interstate Highways

I-90 in Butte, overlooking the copper mines.

A small number of Interstate Highways traverse Montana. Interstate 15 is the state ‘s only north-south route and runs through the west of the state, via Butte, Helena and Great Falls to the border with Canada. Interstate 90 runs west to east through the state, passing through Missoula, Butte, Bozeman, and Billings. Interstate 94 branches off I -90 in Billings and heads northeast. I-94 is one of the quietest stretches of Interstate Highway in the United States. The main intersection of Interstate Highways is the town of Butte, where I-15 and I-90 converge and are double-numbered for a short while.

Interstate 115 is a short 2- kilometer spur of I-15/90 in Butte. Interstate 315 is a short, unsigned, 1 -kilometer Interstate Highway in Great Falls.

The Interstate Highways in Montana are mostly light driven. Traffic is almost never busy, the main truck corridor is I-90 and to a lesser extent I-15. Traffic volumes are particularly low on I-94 in the east of the state.

US Highways

US 12 in Eastern Montana.

A number of US Highways traverse Montana. Most of these are only lightly ridden. US 2 forms a long east-west route through the north of the state, via Kalispell, Shelby and Malta to the border with North Dakota. This road leads through the Bakken Formation where a lot of oil is extracted in the border area with North Dakota. US 12 forms an east-west route through the south of the state, passing through Missoula, Helena and Miles City. Between I-90 and Helena, US 12 is one of the most important stretches of US Highway in the state. US 20 runs just a few miles through the extreme south of the state. US 87 forms a north-south route in the east and center of the state, through Billings to Great Falls. This is an inland route to Canada.

US 89 forms a north-south route in the center of the state, from Yellowstone National Park through Livingston to Great Falls, and on to the border with Canada. Before the construction of I-15, this was the primary route between Montana and Alberta. US 93 forms a north-south route through the west of the state, passing through Missoula and Kalispell. US 191 forms a north-south route through the center of the state, from West Yellowstone through Bozeman and Lewistown to the border with Canada. Partly known as the Beartooth Highway in the mountains, US 212 runs through the southeastern part of the state, from Yellowstone through Billings to the far southeastern part of the state. The eastern part of US 212 is very light. US 287 is a north-south route in the west of the state and of less importance because it runs partly parallel to I-15. US 310 runs just a short stretch north-south through the south of the state and is primarily a route from Billings to some small towns in northern Wyoming.

In Montana, almost no US Highways are constructed as a 2×2 divided highway, only short stretches in the larger towns. This is in contrast to states further east on the Great Plains where major corridors have often been widened to 2×2 lanes. However, the traffic volume in many parts of Montana is too low to justify such an investment. US 87 from Billings to Great Falls is considered a priority corridor as part of the Camino Real Corridor, but no steps have been taken to improve the section in Montana.

State Highways

The Highway 28.

In Montana there is a network of state highways that mainly supplements the US Highways. Due to the low population density, there is hardly a real network, most state highways are connections between US Highways and Interstate Highways, but only to a limited extent between each other. The network of state highways is divided into primary highways and secondary highways. The primary highways are predominantly numbered from 1 to 89, there are only a few three-digit routes, but State Route 200 is the longest in the state, and even the longest state highway of all states in the country, with a length of 1,137 kilometers. Secondary highways are numbered from 200 to 573. There are no state highways in Montana that are designed as freeways.

What is special is that state highways only occasionally run through one of the larger cities in Montana, because the large cities are mainly located at intersections of US Highways and Interstate Highways. For example, there is not a single state highway that passes through Helena or Great Falls, and only one in Butte, Billings, Bozeman and Missoula. State highways therefore often have a secondary character and provide access to small villages and rural areas.

Toll roads

There are no toll roads in Montana, nor were there ever in the motorized era. There were toll roads in the 19th century, from 1864, when Montana became a territory, toll companies were set up to improve the first roads. At its peak in 1868, there were 33 toll companies operating in Montana, which also operated ferry services across the major rivers. In the early 20th century, the toll roads were taken over by the local governments and later by the Montana Highway Department.


US 191 between Big Timber and Harlowtown.

Montana was one of the least developed states in the early 20th century. In 1900, the state had only 243,000 residents, who lived mainly in the west of the state. In particular, the east, the High Plains, was virtually unexplored territory. The development of the road network started mainly in the 1920s. Road numbering was introduced for state highways in 1922, supplemented by US Highways in 1926. The introduction of US Highways made clear which routes were given priority to be paved. In 1935 a large part of the then US Highways had already been asphalted. The least developed routes in 1935 were the later US 12 and US 212 in the center and southeast of the state, as well as US 2 through the Rocky Mountains. Unlike other states, Montana’s minor road network is not widely paved.

The oldest stretch of highway in Montana is a five-mile stretch of I-90 between Drummond and Garrison that opened in 1959. This section coincides with US 12 as part of its route from Missoula to Helena. In 1961, several sections of I-15 and I-90 opened throughout the state. All three of Montana’s Interstate Highways were largely inaugurated in the 1960s and 1970s, but all had missing links until the mid-1980s. Some sections were also constructed as a super two in the first half of the 1960s, which were widened to 2×2 lanes until the mid-1980s. In 1988, the last section of I-15 opened south of Dillon, and is the most recent stretch of Interstate Highway to open.

With the construction of the Interstate Highways, several US Highways have been deleted or changed. US 10 originally ran east-west through all of Montana, but was scrapped after I-90 and I-94 were completed, as the route almost completely coincided with Interstate Highways. The same was true for US 91, which has been replaced by I-15. US 212 originally started in Miles City, the route was later changed to the Beartooth Highway. US 191 was only developed in the early 1960s as an entirely new route between Lewistown and Malta.

Today, the road network is still quite thin, especially in eastern Montana where there are only a limited number of paved roads. Large areas here do not have tarmac roads. The creation of Fort Peck Lake, a large reservoir on the Missouri River created an obstacle to north-south traffic, until 1961 there was no north-south route between Wolf Point to the east and Great Falls to the west, a distance of nearly 500 miles. kilometers. There were, however, some ferry services across the Missouri River.

Montana Road Network