2,642 campgrounds with first-come sites

Every campground below has at least one first-come site: no booking, no confirmation, whoever shows up first gets it. That is not the same at all of them. 2,080 never take a reservation, any time of year. 551 keep some sites for online booking and leave the rest first-come, year-round. 11 book online for part of the year and go first-come for the rest of it. Check the label next to each name, and the campground's own page, before you count on a walk-up site.

For the ones that are first-come all year, arrive on a weekday morning, pick a site, and drop cash in the iron ranger. Carry a backup in case the campground is full when you get there.