Montana Snowbowl has more than 30 runs, reaching up to three miles long, and a 2,600-foot vertical drop (406/549-9696 or 800/728-2695, www.montanasnowbowl.com [1]). It’s about 12 miles out of town, reached by taking the Reserve Street exit from I-90 and driving north on Grant Creek Road to Snowbowl Road. Lift tickets at Snowbowl are $36 for adults, $15 for children, with student, senior, and half-day rates available. Both skis and snowboards can be rented, and lessons are available.
There's also challenging cross-country skiing up Pattee Canyon, and the Rattlesnake National Recreation Area and Wilderness (RNRAW) has miles of trails; many are suitable for skiing. Consult the RNRAW map, available at outdoors stores, for possibilities.
In the Garnet Range, east of Missoula [2], the Garnet Resource Area (406/329-3914, $3 adult) is a Bureau of Land Management (BLM)-operated ghost mining town with 55 miles of cross-country ski and snowmobile trails. From State Highway 200, about 30 miles east of Missoula, turn south between mile markers 22 and 23. Or follow I-90 to Bearmouth 26 miles and turn north five miles on Highway 10 to Bear Gulch Road. Follow the signs for Garnet.
Links:
[1] http://www.montanasnowbowl.com
[2] http://www.moon.com/destinations/montana/missoula-and-northwestern-montana/missoula