itOpened Guides · Yellowstone National Park
How to actually get a site at Mammoth Campground (Yellowstone) — the verified facts, the release reality, and the cancellation route in.
Overview Starting Tuesday April 15th, the Mammoth Campground is open and reservations are required. For reservations at the campgrounds managed by Yellowstone National Park Lodges (Fishing Bridge RV Park, Bridge Bay, Canyon, Madison, and Grant Village campgrounds), please visit the Yellowstone National Park Lodges Camping website. Recreation There are many recreational opportunities in the Mammoth Hot Springs and the North area. Visit these pages to learn more: Boating Fishing Hiking Photography & Wildlife Watching Explore the boardwalks above Mammoth Hot Springs to view the the steaming Hydrothermal Features or take a drive around the vibrant travertine terraces. Explore in Winter. Ski or snowshoe among the whiffs of sulfur along the Upper Terraces.
| Total sites | 87 |
|---|---|
| Site types | Standard |
| Site mix (directory count) | Standard 81 |
| Area | Yellowstone National Park |
| Managed by | National Park Service |
| Nearest community | Yellowstone, WY |
| Activities | Amphitheater, Auto Touring, Birding, Camping, Cross Country Skiing, Cultural Activities, Fishing, Hiking, Historic & Cultural Site, Interpretive Programs, Skiing, Visitor Center, Wildlife Viewing |
| Directory phone | 307-344-2107 |
| Official listing | Recreation.gov campground page |
| Book through | Recreation.gov |
Mammoth Campground (Yellowstone) is reserved through Recreation.gov, on the release pattern stated in its official listing. In demand, reservable sites are claimed within minutes of each release — which is why the campground reads as sold out for most of the year, and why the realistic route in is rarely the release itself.
Sites booked months ahead get cancelled as trips fall through, and each cancellation returns its nights to the official calendar instantly — first-come, no waitlist, no announcement. itOpened scans the Recreation.gov calendar for Mammoth Campground (Yellowstone) around the clock; when a site matching your dates and vehicle opens, you get a text with a direct link, and you book it yourself, in your own account, at the normal price. We never book, hold, or resell. The mechanics are the same ones documented in how campsite cancellations actually work.
Watch more than one calendar. These nearby or same-area campgrounds take the same trip — and their cancellations are independent chances:
| Lewis Lake Campground | 84 sites · same area |
|---|---|
| Indian Creek Campground (WY) | 73 sites · same area |
| Tower Fall Campground | 33 sites · same area |
| Slough Creek Campground | 17 sites · same area |
| Eagle Creek Campground - Custer Gallatin National Forest | 20 sites · nearby alternative |
| Bear Creek Campground - MT | 1 sites · nearby alternative |
Full directory facts and sibling campgrounds: Mammoth Campground (Yellowstone) campground page · Yellowstone National Park park page.
Every figure in this article traces to one of the sources above. If a number isn't sourced, we don't print it.
Last updated 2026-10-30.