US 93 enters Montana from Idaho at Lost Trail Pass and travels north descending through the Bitterroot National Forest. The highway continues along the Lewis and Clark Trail into the Bitterroot Valley toward Missoula, passing through Darby and Hamilton. At Lolo, US 12 joins from the west and they run concurrently northeasterly for, where US 93 heads due north on Reserve Street in Missoula. US 93 then joins I-90 and runs concurrently westward for to Wye, where it heads north. is used by grizzly and black bears. From Wye, US 93 continues north through the Flathead Indian Reservation, where its signage includes the historic Salish and Kutenai names for towns, rivers, and streams. Portions of this section run along the National Bison Range. North of the reservation, US 93 traverses the western shore of Flathead Lake, the largest freshwater lake west of the Mississippi River. North of the lake the highway runs through the cities of Kalispell and Whitefish, traveling through the Flathead National Forest and the Stillwater State Forest before reaching its terminus at the Canadian border near Eureka. The portion north of Hamilton travels through one of the most densely populated areas in Montana. This section also serves as a popular north–south connection between Yellowstone National Park and Glacier National Park. As a result, the road tends to become more congested between Hamilton and Whitefish. A popular bumper sticker in Montana reads, "Pray for me, I drive Hwy 93!" Total US 93 mileage in Montana as of 2013 is : from the Idaho line to Reserve Street in Missoula via corridor N-7 , via corridor N-92 , concurrent with I-90 and MT 200, and from Wye to the Canadian border via corridor N-5 .
History
The Lewis and Clark Expedition became the first white men to travel the future US 93 corridor between today's Lost Trail Pass and Lolo in 1805, and Lewis's detachment ventured further north to the future site of Missoula in 1806 on their way to explore the Marias River. When US 93 was established in 1926, the nature of the highway's construction in Montana's mixture of terrain around glacial lakes, through dense forests and over high mountains was a significant challenge given the construction techniques and equipment of the time. On completed sections, animal-vehicle accidents would prove to be a thorn in the side of traveler and engineer alike. Many stretches have been widened and straightened, or else rerouted in ongoing efforts to improve traffic safety and preserve animals at the same time. Some of the old sections are still in use today, including the original gravel routing from Lost Trail Pass to Sula vía Gibbons Pass and Bitterroot-Bighorn Roads, and old paved sections from Darby to Hamilton, through Missoula via Brooks, Stephens, Orange and West Broadway Streets, through St. Ignatius, north of Ronan to north of Pablo, northeast of Elmo through Dayton, Political Hill Road south of Lakeside, Lakeside Boulevard north of Lakeside, Old US 93 S in Somers, Forest Hill Road north of Somers, and two sections between Whitefish and Eureka. US 93 is now four-lanes from Hamilton to Evaro, through Arlee, north of Ronan to the south edge of Polson, and north of Somers to the south edge of Whitefish. Significant animal conservation efforts have also been accomplished in several areas of the corridor from Hamilton to Missoula, and from Missoula to Polson
Kalispell Bypass
A new US 93 Alternate was built to bypass through traffic around downtown Kalispell, Montana, between 2010-2016. Currently, US 93 through Kalispell is Main Street and Sunset Boulevard, a arterial. Three segments of the bypass comprising a total of were completed and opened to traffic between 2010 and 2013. The remaining opened on October 28, 2016. The southwest segment of the bypass is currently only two lanes and is slated for expansion to four lanes with two additional grade-separated interchanges when funding permits.
Major intersections
US 93 does not maintain contiguous mileposts across Montana as US 2 does. The state road log defines US 93 over four sections as of the 2013 edition, as determined by the change in milepost numbers.
