 There are 24 areas where snowmobile trails are maintained, most also offering ungroomed trails.West Yellowstone offers a large selection of trails and is the primary starting point for snowmobile trips into Yellowstone National Park, where "oversnow" vehicle use is strictly limited, usually to guided tours, and regulations are in considerable flux.Snow coach tours are offered at Big Sky, Whitefish, West Yellowstone and into Yellowstone National Park.