Missoula is a small, picturesque college town located at the intersection of five valleys. Missoulians enjoy a range of outdoor activities including hiking, rafting, "tubing", rock climbing, skiing, fishing, folfing, and just about any other activity that can be done outside. It's no wonder—in Missoula you can take a city bus to within walking distance of federally designated wilderness area. After hiking and returning to town, you can visit the historic downtown and enjoy some fantastic local food and drink.
Though US Interstate 90 passes through Missoula, be aware that road trips in Montana can be long. In winter, road conditions can be very hazardous.
The life of Missoula is its historic downtown. And the downtown can be covered by foot. Otherwise, there is reasonable bus service, and sparse (but free) trolley service.