How this is measured

Every number here comes from a federal record. Where a record is silent, this site says so instead of estimating. A confident wrong answer about whether your rig fits costs you more than no answer at all.

The source

All facility and campsite data comes from theRecreation Information Database (RIDB), the federal government's public catalogue of recreation facilities. It covers the National Park Service, Forest Service, Bureau of Land Management, Army Corps of Engineers, Bureau of Reclamation and Fish & Wildlife Service. Federal works are public domain.

Elevation comes from the USGS Elevation Point Query Service, also public domain. Every campground page lists its own sources with the date we retrieved each one.

Data last retrieved 2026-08-17.

How “fits” is decided

RIDB lists the equipment permitted on a site (RV, trailer, fifth wheel, pop-up, pickup camper, camper van) and each type carries its own length limit. They frequently disagree. At Anthony Lake site 20 a pop-up may be 21 ft and a trailer 9 ft. At Alta site 11 a fifth wheel may be 55 ft where the RV entry says 40.

So the rig you pick decides which limit the page reads. Pickingfifth wheel reads the fifth-wheel figure, falling back to the trailer and pop-up figures if that site does not state one, never to the motorhome figure, because a fifth wheel is not a motorhome. Where no equipment limit applies at all, the page falls back to two weaker measurements, in order:

1. Maximum vehicle length, the site's general vehicle limit.
2. Driveway length, the measured pad. Weakest of the three, because a pad is not the same claim as a permitted vehicle.

A site whose permitted equipment is only tents or horses is never counted as fitting, whatever its driveway measures. That is16,129 of 115,481 sites, and reading their driveway length as a rig limit is the single largest way a listing like this can tell you something fits when it does not.

Each site tile says which of the three answered. Ignoring the weaker two would discard 87,506 of115,481 sites as “no length published” when they do publish one.

A site publishing none of the three is never counted as fitting. It is shown as unknown. Some agencies write 0 where a length does not apply (a tent-only site, for instance) and a zero stored as a measurement would classify that site as too short rather than unmeasured. The loader takes those as absent.

Why the advertised number misleads

Apps and listings show a campground's “max RV length”. That figure is the longest single site on the property. Of the 3,412 campgrounds here with more than ten sites, 635 advertise a length that exactly one site achieves. This site counts how many of a campground's sites take your length, which is the question that matters.

What is excluded

• 12,359 non-site records. Camp-host slots, fee placeholders and scan-and-pay rows arrive from the source as campsites, and nobody can book any of them. We keep them for provenance and leave them out of every count.
• Cabins and guard stations. Real rentals, but not places to park a rig. The loader classifies them separately and never ranks them alongside campgrounds.
• Campgrounds with no site-level data. Roughly a third of the corpus. They remain reachable but are not offered as answers, because they cannot answer the question.

Of 7,082 facilities, 2,179 carry enough data to be worth ranking. The rest are reachable and honest about what they lack.

A structural limit worth knowing

RIDB holds site-level detail only where a campground is reservable. This holds without exception across every facility checked. First-come, first-served campgrounds have no inventory recorded anywhere in the federal system, so this site cannot tell you whether your rig fits at one. That is a property of the source, not an omission here, and no amount of work on our side changes it.

How this is made

A worker fetches the data, normalises it and compiles it into a verified database offline; the site only reads it. Nothing on a campground page is generated prose. The words come from a fixed template, and the rest is the agency's own record, presented as theirs.

The notes are different, and this is the disclosure that matters. A language model drafts them and a person edits them against gates. Every figure in a note is registered with the query that produces it and rechecked against the database on every build, so a number that drifts fails the build instead of serving. The prose itself is measured for the register a model reaches for when nobody is watching: the stock vocabulary, the em dash as rhythm, the tidy summary ending. No note carries a claim the corpus cannot support, and no byline here belongs to a person who does not exist.

Corrections

If a measurement here disagrees with what you found on the ground, every campground page links the source record, and the agency is the authority. Book through Recreation.gov, the official system. This site takes no cut and sells nothing.