Missoula is an amazing place for biking, I agree. I wish, however, the riding on the sidewalk situation could be "friendlier" to all involved. Too many accidents between motorists and sidewalk cyclists, unaware/unsuspecting from both parties involved.
There is a great bicycle safety video, from the 60's, called One Who Got Fat. Check it out - a Missoulian (who shall remain anonymous) is one of the monkeys!