# List of U.S. Highways in Montana

The U.S. Highways in Montana are the segments of the United States Numbered Highway System owned and maintained by the Montana Department of Transportation (MDT) in the U.S. state of Montana.

## Mainline highways

| Number | Length (mi) | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes |
| US 2 | 667 | 1,073 | US 2 west of Troy | US 2 east of Bainville | 01926-01-011926 | current | |
| US 10 | 700 | 1,100 | US 10 near Mullan, ID | US 10 near Beach, ND | 01926-01-011926 | 01986-01-011986 | Mostly replaced by I-90 and I-94 |
| US 10N | 112 | 180 | Three Forks | Garrison | 01930-01-011930 | 01959-01-011959 | Replaced by MT 287 and US 12 |
| US 10S | 115 | 185 | Three Forks | Garrison | 01930-01-011930 | 01959-01-011959 | Became mainline US 10 |
| US 12 | 597 | 961 | US 12 near Lolo Hot Springs | US 12 near Marmarth, ND | 01926-01-011926 | current | |
| US 20 | 10 | 16 | US 20 near West Yellowstone | Yellowstone National Park entrance at West Yellowstone | 01940-01-011940 | current | |
| US 87 | 440 | 710 | I-90/US 87 near Ranchester, WY | US 2 at Havre | 01926-01-011926 | current | |
| US 87E | 311 | 501 | Armington | US 87E near Ranchester | 01926-01-011926 | 01934-01-011934 | Became mainline US 87 |
| US 87W | 209 | 336 | Armington | Yellowstone National Park near Gardiner | 01926-01-011926 | 01934-01-011934 | Replaced by US 89 |
| US 89 | 404 | 650 | Yellowstone National Park near Gardiner | Hwy 2 near Carway, AB | 01934-01-011934 | current | |
| US 91 | 396 | 637 | US 91 near Monida | Hwy 4 at Sweetgrass | 01926-01-011926 | 01980-01-011980 | Replaced by I-15 |
| US 93 | 286 | 460 | US 93 at Lost Trail Pass | BC 93 at Roosville, BC | 01926-01-011926 | current | |
| US 191 | 438 | 705 | Yellowstone National Park at West Yellowstone | Hwy 4 north of Loring | 01926-01-011926 | current | |
| US 212 | 322 | 518 | Yellowstone National Park at northeast entranceUS 212 south of Red Lodge | US 212 near Cooke CityUS 212 near Alzada | 01939-01-011939 | current | |
| US 287 | 282 | 454 | Yellowstone National Park entrance at West Yellowstone | US 89 at Choteau | 01965-01-011965 | current | |
| US 310 | 55 | 89 | US 310/WYO 789 near Frannie, WY | I-90 Bus. at Laurel | 01926-01-011926 | current | |
| US 312 | 225 | 362 | US 12 in Billings | US 212 at Broadus | 01959-01-011959 | 01981-01-011981 | Replaced by MT 59 and US 10 |
| US 789 | — | — | Wyoming state line near Frannie | Canadian Border near Sweetgrass | — | — | Proposed, but never commissioned; would have followed (south to north) US 310, US 10/US 212, US 87, US 91 |
| Former ||||||||

## Special routes

| Number | Length (mi) | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes |
| US 10A | 142 | 229 | De Smet | US 10A near Heron | 01941-01-011941 | 01967-01-011967 | Replaced by MT 200 |
| US 10A | 62 | 100 | Opportunity | Drummond | 01936-01-011936 | 01986-01-011986 | Replaced by MT 1 |
| US 10 Byp. | — | — | — | — | — | — | Served Butte |
| US 10S Byp. | — | — | — | — | — | — | Served Butte |
| US 10 Byp. | — | — | — | — | — | — | Served Billings |
| US 12 Bus. | — | — | — | — | — | — | Serves Missoula |
| US 10 Bus. | — | — | — | — | — | — | Serves Helena |
| US 10 Byp. | — | — | — | — | — | — | Served Helena |
| Temp. US 10 | — | — | — | — | — | — | Served Fallon and Ismay |
| US 87 Bus. | — | — | — | — | — | — | Serves Great Falls |
| US 89 Byp. | — | — | — | — | — | — | Served Great Falls |
| US 91 Byp. | — | — | — | — | — | — | Served Butte |
| US 91 Byp. | — | — | — | — | — | — | Served Helena |
| US 93 Alt. | 4.5 | 7.2 | US 93 south of Kalispell | US 93 north of Kalispell | 02010-01-012010 | current | Included all segments open as of November 2013; expected completion in 2016 |
| US 191 Bus. | — | — | — | — | — | 02025-02-182025 | Served Lewistown |
| US 212 Byp. | — | — | — | — | — | — | Served Billings |
| Former ||||||||