An Outdoorithm Study
The Sellout Index
America’s hardest-to-book campgrounds — measured, not guessed. Our scanners watch campsite inventory across 44 reservation systems around the clock and record every released site appearing and being booked away. This is where the sites vanish fastest.
92%
of released sites at ranked campgrounds get re-booked
~16m
typical bookable window at the fastest campground on the list
33
campgrounds with enough measured history to rank
The ranking
Ranked by Sellout Score — how often released sites get re-booked, weighted by how fast they vanish. Every number below was observed by our scanners at that campground.
- 82% re-bookedsites reopen 40×/wkstay bookable ~16m36 openings measured
- 100% re-bookedsites reopen 7.5×/wkstay bookable ~45m59 openings measured
- 95% re-bookedsites reopen 5.3×/wkstay bookable ~41m40 openings measured
- 98% re-bookedsites reopen 12×/wkstay bookable ~1h113 openings measured
- 97% re-bookedsites reopen 15×/wkstay bookable ~1h195 openings measured
- 97% re-bookedsites reopen 13×/wkstay bookable ~1h57 openings measured
- 97% re-bookedsites reopen 60×/wkstay bookable ~1h567 openings measured
- 96% re-bookedsites reopen 27×/wkstay bookable ~3h52 openings measured
- 81% re-bookedsites reopen 6.5×/wkstay bookable ~55m13 openings measured
- 70% re-bookedsites reopen 5.3×/wkstay bookable ~2h23 openings measured
- 81% re-bookedsites reopen 10×/wkstay bookable ~6h48 openings measured
- 95% re-bookedsites reopen 2.9×/wkstay bookable ~7h19 openings measured
- 85% re-bookedsites reopen 6.4×/wkstay bookable ~12h44 openings measured
- 96% re-bookedsites reopen 11×/wkstay bookable ~12h26 openings measured
- 98% re-bookedsites reopen 5.6×/wkstay bookable ~15h45 openings measured
- 95% re-bookedsites reopen 9.8×/wkstay bookable ~9h18 openings measured
- 92% re-bookedsites reopen 1.8×/wkstay bookable ~6h12 openings measured
- 71% re-bookedsites reopen 9.3×/wkstay bookable ~14h30 openings measured
- 96% re-bookedsites reopen 58×/wkstay bookable ~24h400 openings measured
- 96% re-bookedsites reopen 34×/wkstay bookable ~5d47 openings measured
- 94% re-bookedsites reopen 100+×/wkstay bookable ~22h241 openings measured
- 92% re-bookedsites reopen 58×/wkstay bookable ~24h440 openings measured
- 92% re-bookedsites reopen 24×/wkstay bookable ~24h154 openings measured
- 91% re-bookedsites reopen 5.7×/wkstay bookable ~47h31 openings measured
- 92% re-bookedsites reopen 100+×/wkstay bookable ~24h974 openings measured
- 73% re-bookedsites reopen 100+×/wkstay bookable ~15h2265 openings measured
- 90% re-bookedsites reopen 78×/wkstay bookable ~24h208 openings measured
- 91% re-bookedsites reopen 100+×/wkstay bookable ~23h5344 openings measured
- 60% re-bookedsites reopen 36×/wkstay bookable ~13h34 openings measured
- 83% re-bookedsites reopen 100+×/wkstay bookable ~24h155 openings measured
- 94% re-bookedsites reopen 2.4×/wkstay bookable ~34h16 openings measured
- 94% re-bookedsites reopen 3.1×/wkstay bookable ~19h15 openings measured
- 67% re-bookedsites reopen 1.8×/wkstay bookable ~24h10 openings measured
Sold out isn’t the end of the story
Cancellations happen constantly — that's what this whole page measures. Set a watch on any campground above and we’ll notify you the moment a site opens, with a booking link that lands on your dates.
How campsite alerts work →How we measure this
Outdoorithm runs automated availability scans across 44 public-land reservation systems — Recreation.gov, ReserveCalifornia, state park systems, and more. Every time a previously-booked campsite becomes available, our scanners record it appearing; when it gets booked again, they record it gone. Each row above summarizes those lifecycles at one campground.
Re-booked is the share of released sites someone else took. Sites reopen is how often new availability appeared over the trailing 90 days. Stay bookable is the median time a released site remained available — measured at our scan interval, so it’s an upper bound: the fastest sites vanish quicker than we can observe.
The Sellout Score combines scarcity (re-booked share) with urgency (how fast sites vanish), damped by sample size so a campground with a handful of observations can’t top the list. We only publish campgrounds with at least ten measured openings where at least half of released sites got re-booked; our scanners currently watch 126 campgrounds, and the list grows as more people set watches in new places.
Statistics refresh nightly from live scan data. This page is descriptive, not a guarantee — booking odds shown on campground pages carry the same measured-upper-bound caveats.