Mammoth Campground is a busy campground near Gardner, Montana, and the northwest entrance of Yellowstone National Park. The campground is nestled between a large curve in the road below the town of Mammoth Hot Springs. Mammoth Campground is one of seven first-come, first-served campsites in the park. Campsites tend to fill between 8:00 a.m. and 11:00 a.m., with lines to reserve campsites starting around 6:00 a.m. If you arrive in line after 9:00 a.m., there is little chance of obtaining a site on that day. This is the case for all first-come, first-served campgrounds in the park. The bottom row of the campsite has the best views, while the middle row is the quietest, and the top row is the most private. Both the top and bottom rows are very close to the main road and have substantial noise from traffic entering and exiting the park.
The view in the campground is dominated by the broad face of Mount Everts. Mount Everts was once the basin of a valley, but rapid lifting and erosion from the Gardiner River have created the impressive mountain you see today. The multiple layers such as ridge tuff, shale, and sea bed sediments are an impressive visual example of the rich geologic history of Yellowstone.
A short hiking trail to Mammoth Hot Springs gives you access to a grocery store, a gas station, a ranger station, a backcountry ranger station, a gift shop, and a post office. Evening educational talks are given each night in the auditorium at the top row of the campsite. Fresh drinking water and bathrooms are also conveniently located at multiple areas throughout the campsite, but no showers are available.