Lolo peak is a popular area for doing backcountry, as well as the point six and murphy peak area that can be accessed through snowbowl. The southern end of the missions typically get more snow, so places such as trapper peak are good areas for that.
Most of the mountains east of Missoula and Bitterrot valley are drier during the winter, since the bitterroots suck up so much moisture and create a snow shadow east of the range.