In the U.S. state of

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

, Interstate 15 (I-15) continues onward from

Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

for nearly through the cities of

Butte In geomorphology, a butte ( ) is an isolated hill with steep, often vertical sides and a small, relatively flat top; buttes are smaller landforms than mesas, plateaus, and table (landform), tablelands. The word ''butte'' comes from the French l ...

, Helena, and Great Falls, intersecting with I-90, I-115, and I-315. I-15 reaches its northern terminus at the international border with

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

, Canada. I-15 is additionally named as the First Special Service Force Memorial Highway from Helena to the Alberta border, where Alberta Highway 4 continues into Canada retaining that designation. I-15 joins with I-90 and makes a junction with a short, spur route I-115 in

Route description

I-15 crosses into Montana from Idaho just south of Lima Reservoir over Monida Pass, at , the highest elevation on the entire route of I-15. The route continues northwest through farmland and desert. The freeway turns north at Clark Canyon Reservoir, before turning northeast. In the town of Dillon, I-15 passes near Clark's Lookout State Park before beginning to parallel the

Big Hole River The Big Hole River is a tributary of the Jefferson River, approximately 153 miles (246 km) long, in Beaverhead County, Montana, Beaverhead County, in southwestern Montana, United States. It is the last habitat in the contiguou ...

. The freeway then turns away from the river, continuing northeast along Divide Creek through the desert, before splitting away from the creek and heading north. I-15 eventually merges into I-90 at a trumpet interchange. I-15 and I-90 run concurrently through the city of

, coming first to an interchange with I-115, signed as Business Loop 15 and Business Loop 90. I-15 and I-90 pass through a green area in the middle of the city, before I-15 splits off to the northeast on the eastern end of the town. The freeway climbs along the eastern edge of the Continental Pit mine, and then over continental divide at Elk Park Pass. I-15 travels through the forest and plains of Elk Park before winding along Bison Creek and later the Boulder River. I-15 passes through the town of Basin before leaving the mountains and providing access to

Boulder In geology, a boulder (or rarely bowlder) is a rock fragment with size greater than in diameter. Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive. In ...

. Paralleling Beavertown Creek, the road winds through the hills before passing through Jefferson City. The freeway continues into Helena, where I-15 intersects US 12 and runs concurrently with US 287 through the outskirts of the city before continuing north through the plains. I-15 and US 287 continue along Little Prickly Pear Creek before passing through the town of Wolf Creek after several miles. Northeast of there, US 287 continues north, while I-15 runs close to the

Missouri River The Missouri River is a river in the Central United States, Central and Mountain states, Mountain West regions of the United States. The nation's longest, it rises in the eastern Centennial Mountains of the Bitterroot Range of the Rocky Moun ...

. The freeway provides access to Cascade and then continues through the plains through Ulm before turning northeast into the city of Great Falls. I-315 and US 89 intersect with I-15 at a trumpet interchange, and US 89 continues north and then northwest along I-15 for a few miles before continuing to the west. I-15 continues northwest through farmland before passing near Dutton and Brady, and the city of Conrad. US 2 intersects I-15 in the town of Shelby. The freeway passes through the town of Sunburst, then passes through a final stretch of farmland. Eventually, I-15 passes through the last town before Canada, Sweet Grass, and then crosses the international border, becoming Alberta Highway 4.

History

In 1996, I-15 between Helena and Sweet Grass was renamed the "First Special Service Force Memorial Highway". It was chosen because it was the route taken in 1942 by the Canadian volunteers to join their American counterparts for training at Fort Harrison.

Exit list

References

External links

{{state detail page browse, type=I, route=15, state=Montana, statebefore=Idaho 15 Montana Transportation in Beaverhead County, Montana Transportation in Madison County, Montana Transportation in Silver Bow County, Montana Transportation in Jefferson County, Montana Transportation in Lewis and Clark County, Montana Transportation in Cascade County, Montana Transportation in Teton County, Montana Transportation in Pondera County, Montana Transportation in Toole County, Montana