There are some great nordic skiing areas throughout Montana, and a fair number near Missoula.

Missoula Nordic Club does a great job grooming three areas near town.  Check out their grooming report for trail conditions on several areas both near to town and a half hour away.

North Shore Nordic Club has good info on two nordic centers in the North Flathead – one outside of Bigfork and one at Blacktail Mountain out of Lakeside.