Yellowstone is sold out.
Here's what to do.

Yellowstone receives over 4 million visitors per year. Most reservable campgrounds open 5–6 months in advance and sell out within days. Madison, the most popular, books out within hours of the reservation window opening. The park has about 2,000 total campsites spread across 12 campgrounds.

Mammoth Campground is the easiest — it is open year-round and has more cancellation turnover than summer-only sites. Slough Creek (29 sites, Lamar Valley) is first-come first-served — arrive by 8am. Indian Creek and Pebble Creek campgrounds in the north are also first-come with good availability in shoulder season.

Yes — Gardiner MT (north entrance) has several private campgrounds. West Yellowstone MT has KOA and other options just outside the west entrance. Grand Teton National Park is 30 miles south and has Signal Mountain Campground and Colter Bay with more availability. Set a CamperWatch alert and book nearby while waiting for an in-park cancellation.

Recreation.gov processes cancellations and releases sites daily at 7:00 AM Mountain time. Midweek slots (Sunday–Thursday arrivals) cancel more frequently. Set a CamperWatch alert to be notified immediately — we scan every 10 minutes.

Madison Campground is considered the best overall — central location between Old Faithful and the Grand Prismatic Spring, 278 sites, and good facilities. For wildlife, Slough Creek in Lamar Valley is exceptional but first-come only. Mammoth is the only year-round option.