The rental agent will call it a 25-footer. The ranger at Zion’s East Entrance will want the width including the mirrors, to the inch, and Recreation.gov will want the length of the whole unit before it shows you a site. Enter your numbers once and see where the vehicle you are quoted actually fits, before you pay a deposit.
Where your RV fits
Enter your length to start.
“Fits” means at least half of the RV sites list a length that takes yours; “Some sites” means fewer; “Check” means official sources disagree or give no number. A fitting site still has to be free: this tool doesn’t check availability. The page address updates as you type, so you can bookmark it or send it to whoever you travel with. Nothing you enter leaves your browser.
Limits change. These are the limits as published, checked 2026-10-28; Zion’s highway limits apply since June 7, 2026 [R1], and the five Yellowstone campgrounds run by the lodge operator move to Recreation.gov for 2027 [R8]. Before you book, open the site’s own listing on Recreation.gov and check its “Max Vehicle Length” [R2]. Not legal advice; a planning aid [A].
How to measure (or what to ask the rental company)
- Length: bumper to bumper, including a rear bike rack, ladder or spare wheel. Campgrounds count the whole unit: motorhome plus anything towed [R2][R5].
- Width: with the mirrors folded out as you drive. Zion counts mirrors, tires and attachments [R1]. Many Class C motorhomes are around 8 ft wide before mirrors, so the Zion width limit of 7 ft 10 in is where they fail [A].
- Height: to the top of the roof A/C, vents or anything mounted on the roof [R1].
- Get it in writing: ask the rental company for exact length, width with mirrors and height for the model you are quoted, before you pay a deposit. Fleets sometimes hand out a different model at pickup, so ask what happens if the substitute is bigger [A].
How the checker works
- Zion: compares your numbers with the limits for the whole road between Canyon Junction and the East Entrance: single vehicles, or combined vehicles if you tow [R1]. Within 2 inches (5 cm) of a limit, it warns you [A].
- Campgrounds: first the campground’s published limit (NPS, Recreation.gov, Arizona State Parks) [R3]–[R10]. Then, for the 25 Recreation.gov campgrounds, we count how many sites list a maximum length that takes yours, for your vehicle type: campervan, motorhome, or trailer [R2]. Where Recreation.gov lists no length for more than a fifth of the sites, we show only the campground limit.
- Where sources disagree (Mammoth, Lizard Creek), the tool says “Check” and explains both figures [R7][R8].
- Roads and parking: the size rules from our RV size limits guide, for each route [R3][R4][R9][R11][R12].
- Not covered: availability, hookups for your power needs, private RV parks and rental-contract road bans. Width and height limits exist only on roads here; campgrounds on our routes publish length only (except Jenny Lake) [R2][R7].
Next step
What to book whenThe opening date and time for each campground that fits, in your time zone
Sources and how we checked
Every limit in the checker comes from these pages, opened on 2026-10-28. [A] marks our own advice and estimates.
- [R1] NPS Zion — Large Vehicles (single vehicle 35 ft 9 in long, 7 ft 10 in wide, 11 ft 4 in high, 50,000 lb; combined vehicles 50 ft total, trailer max 26 ft from hitch to rear axle; measurements include mirrors, tires and attachments such as A/C units and bike racks; vehicles over any limit are turned around; South Entrance exceptions; UT-20 detour about 150 miles, 2.5 hours; page last updated September 2, 2026) — www.nps.gov/zion/planyourvisit/large-vehicles.htm (checked 2026-10-28)
- [R2] Recreation.gov — campground pages and the individual campsite listings ("Max Vehicle Length" for each permitted equipment type) for the 25 Recreation.gov campgrounds in this tool, read on 2026-10-28; Watchman loops C and D: no vehicles 19 ft or longer. Raw data in our build notes — www.recreation.gov (campground and campsite pages) (checked 2026-10-28)
- [R3] NPS Bryce Canyon — Oversized Vehicle Restrictions (23 ft and longer; shuttle season typically mid-April to mid-October; 8 am–8 pm, to 6 pm in April and October; Paria View always) and Campgrounds (North all year, Sunset closed in winter; page last updated March 25, 2026) — www.nps.gov/brca/…/oversized-vehicle-restrictions.htm (checked 2026-10-28)
- [R4] NPS Grand Canyon — Visiting the South Rim in an RV (over 22 ft; lots 1, B and D), Hermit Road (private vehicles under 22 ft, December–February only) and the public health update (Stage 4 water restrictions); Recreation.gov — Mather and Desert View (30 ft) — www.nps.gov/grca/planyourvisit/rv.htm (checked 2026-10-28)
- [R5] Recreation.gov — Devils Garden Campground, Arches (site limits from 23 to 40 ft) and The Needles Campground, Canyonlands (28 ft maximum combined length) — www.recreation.gov/camping/campgrounds/234059 (checked 2026-10-28)
- [R6] NPS Capitol Reef — Fruita Campground (71 sites, no hookups, dump station and water fill between loops A and B, reservation only; page last updated April 1, 2026); site lengths from Recreation.gov [R2] — www.nps.gov/care/planyourvisit/fruitacampground.htm (checked 2026-10-28)
- [R7] NPS Grand Teton — Camping (Gros Ventre, Colter Bay and Headwaters 45 ft; other campgrounds 30 ft) and Recreation.gov — Jenny Lake (tents only, vehicles 14 ft long, 8 ft high), Lizard Creek (25 ft), Colter Bay RV Park (back-in 30 ft, pull-through 45 ft) — www.nps.gov/grte/planyourvisit/camping.htm (checked 2026-10-28)
- [R8] NPS Yellowstone — Camping ("RV + vehicle max length" per campground; Mammoth 45 ft May to mid-October, 30 ft in winter; Slough Creek "assess first"; Tower Fall hairpin curve; Fishing Bridge hard-sided only; no RV deliveries to campsites; page last updated February 25, 2026) — www.nps.gov/yell/planyourvisit/campgrounds.htm (checked 2026-10-28)
- [R9] NPS Rocky Mountain — Campgrounds (Aspenglen 30 ft, Glacier Basin 35 ft, Moraine Park 40 ft, Timber Creek 30 ft, Longs Peak tents only; page last updated October 22, 2026) and Old Fall River Road (no vehicles over 25 ft, no trailers) — www.nps.gov/romo/planyourvisit/camping.htm (checked 2026-10-28)
- [R10] Arizona State Parks — Camping at Dead Horse Ranch ("most of the pull-through sites can accommodate 40-foot motor homes and truck and trailer rigs up to 65 feet"; Blackhawk Loop tents only, no campers or vans; generators prohibited) — azstateparks.com/dead-horse/…/camping-at-dead-horse-ranch (checked 2026-10-28)
- [R11] ADOT — SR-89A Oak Creek Canyon Corridor Management Plan (trucks not allowed; vehicles over 40 ft restricted) and Sedona Shuttle — How to ride (RVs, campers and buses not allowed at Park & Ride lots) — azdot.gov (PDF) (checked 2026-10-28)
- [R12] NPS Zion — Zion Canyon Shuttle System (Scenic Drive closed to private vehicles in shuttle season) — www.nps.gov/zion/…/zion-canyon-shuttle-system.htm (checked 2026-10-28)
Not from a source [A]: the 2-inch warning margin, the “Fits / Some sites” threshold, typical rental widths, and our advice on the route via I-17 and on unpaved roads. Site counts are as listed on Recreation.gov on 2026-10-28; a few listings give no length or obviously wrong ones (1–2 ft), and we count those as unknown.
Affiliate note: this page has no affiliate links. Our only affiliate links are marked Amazon links in our gear guides and on a few trip pages; as an Amazon Associate, Runway to Rim earns from qualifying purchases. We don't accept paid rankings. See our disclosure.