There is no public transportation service provided within Yellowstone National Park.
Xanterra Parks Resorts provides bus tours within the park during the summer season. The Lower Loop Tour departs from locations in the southern part of the Park only. The Upper Loop Tour departs from Lake Hotel, Fishing Bridge RV Park, and Canyon Lodge to tour the northern section of the park only. The Grand Loop Tour departs from Gardiner, MT and Mammoth Hot Springs Hotel to tour the entire park in one day. During the winter season, they provide several snowcoach tours from various locations. Please call (307) 344-7311 for information or reservations.
During the summer season, commercial businesses offer tours originating from many area towns and cities. During the winter season, some businesses provide snowcoach tours for most park roads or bus transportation on the Mammoth Hot Springs to Cooke City road.