One of the few Yellowstone campgrounds open year-round, Mammoth sits near the park’s North Entrance and the famous travertine terraces of Mammoth Hot Springs, with elk regularly grazing right through the campground and even the nearby town. Sites offer flush toilets and potable water, no hookups, and the lower elevation here means noticeably milder winters than the rest of the park, making this a genuine option for a shoulder-season or even winter visit when most other campgrounds are closed. Its position near the North Entrance also makes it a convenient base for visitors arriving via Montana rather than Wyoming.