Our transit system here is really a wanna-be. Busses don't run very often and stop running by 8:00 P.M. Standing in 30+MPH winds in -5F temps waiting for a bus is insane. At least if your riding/walking, your generating some heat.
Great Falls is not so big that you can't get from one end of town to the other in a reasonable amount of time on your bike. The city is split by the Missourri River and the Sun River. Riding to the bridges can add some pretty good miles to your trip.