How first-come campgrounds work
2,080 of the 5,569 federal campgrounds on this site take no reservations. That is 37 percent of the total. The figure comes from the Recreation.gov record for each campground, and from Forest Service recreation pages for campgrounds that Recreation.gov does not list. A campground is counted as first-come when neither source gives it a booking page. The full list is at first-come campgrounds, with a page for each of the 28 states that have at least ten.
What first-come means
At a first-come campground a site belongs to whoever occupies it and pays. There is no booking window and no confirmation email. The managing agency posts the rules on the entrance board, and those rules differ from one campground to the next. Some campgrounds have a host who assigns sites. Some have a fee tube where you drop an envelope. Some charge nothing. The campground page on this site shows the fee text and the stay limit from the agency record when the agency published them, and shows nothing when it did not.
The Forest Service runs 82 percent of the first-come campgrounds listed here. National forest campgrounds are often small and far from a ranger station, and many were never set up for reservations.
Reading a first-come record
A first-come campground record on this site carries less than a reservable one. Recreation.gov collects site-level detail, such as driveway length and hookups, only for campgrounds it books. For a first-come campground you will usually see the site count, the season if the agency posted one, the fee text and the coordinates. When the record is thin, the page says so in a note near the bottom.
Where the Forest Service publishes a status for the campground, the page shows it with the date it was checked. That status is the agency's word on whether the campground is open, and it is the only live signal about the campground itself on the page.
Planning a first-come trip
The plan is built around when you arrive and where you go if the campground is full.
Arrive early on the day you want a site. Campers leave in the morning, so a site that was full at dinner may be open by late morning. Checkout time is set by the campground and posted at the entrance.
Pick a second and a third campground before you leave home. The campground page lists the nearest campgrounds by distance with their booking status, so you can see which neighbors are also first-come. The state pages under the first-come list map every first-come campground in the state.
Carry cash or a checkbook. Fee tubes take envelopes, and many first-come campgrounds have no card reader. The fee text on the campground page says what the agency charges when the agency published it.
Check the stay limit. The campground page shows the limit from the agency record when one was published. Where the record is silent, the entrance board is the source.
Confirm the season. A first-come campground in the mountains may be gated until the road is plowed. The Forest Service status, when present, is the best indicator this site has, and the forecast on the page comes from the National Weather Service for the campground's coordinates.
When a first-come campground is full
There is nothing to refresh. Drive to the next one on your list. Free campgrounds on nearby Forest Service or Bureau of Land Management land are the usual fallback. The free campgrounds list covers the 376 campgrounds on this site whose fee record says there is no charge, and most of those are first-come as well.
If you would rather hold a site in advance next time, the reservable list shows the 3,489 campgrounds with a Recreation.gov booking page, by state. The guide to the Recreation.gov reservation window explains how far ahead those open.