Will my rig fit? RV size checker for 20 national parks
Type in your rig's length, height and width and pick its type. The checker compares them with every published campground length limit and road or tunnel restriction we have verified for 20 national parks, from Acadia to Zion, and marks each one fits, flag or over the limit with the exact figure and the NPS or Recreation.gov page it came from. It is for anyone planning a national park trip in a motorhome, fifth wheel, travel trailer or van who wants to know before booking whether the park, or just one loop of one campground, will take them.
Decimal feet: 11 ft 6 in = 11.5. Measure, do not trust the brochure: brochure length often omits the hitch and rear rack, and brochure height omits the air conditioner.
Enter at least a unit length to see results.
Verified 2026-10-28, confirm before booking. Every row links to the page the number came from. Parks change limits and Recreation.gov edits site data; a wrong number here can put you nose-first into a tunnel, so open the link.
How it works, how to use it, and what it does not cover
The checker holds 96 campground rows and 24 road rows for 20 national parks, each with the one number the park actually enforces and a link to where it is published. When you type in your rig, each row is compared with the right measurement: a campground that quotes a "maximum RV or trailer length" is compared with your unit length; one that quotes a combined limit, such as Gros Ventre's 45 ft or Canyonlands' 28 ft, is compared with your total; and one that only publishes per-site driveway lengths on Recreation.gov is compared with your total, then flagged, because the longest site is not the typical site. Roads work the same way, with width and height added where a park posts them, and NPS "not advised" advisories (the Generals Highway's 22 ft, for instance) are shown as flags rather than exclusions because that is what they are.
Use it in this order. Enter the unit length first and look at the park summaries: a green park has at least one campground your rig fits outright, an amber one has only flagged options, a red one has none. Then add the total length, height and width, because that is where the surprises live: a 32 ft Class C with a toad is a 50 ft combination at Zion, and an 8 ft 6 in wide body is over the limit on Going-to-the-Sun Road and the Hetch Hetchy Road regardless of length. Finally open the park you care about and read the reason text on each row; it tells you which specific sites or loops to book (Mather's five 30 ft sites, Blackwoods Loop A, Fishing Bridge's Upper Loop) and which roads to route around.
What it does not cover: state parks, Forest Service and BLM campgrounds (apart from Ken's Lake near Moab), private RV parks outside the gates, and the many national parks not in our guides. It does not know site slope, turning radius, tree overhang or whether a slide-out can open, all of which exclude rigs that pass on paper; Joshua Tree's Cottonwood and Grand Canyon's Desert View both warn about exactly that. It does not check weight, except Zion's 50,000 lb and the Gardner River bridge's 80,000 lb limits, and it does not know the hitch-to-rear-axle distance Zion uses for trailers, so it flags rather than decides. Where two official pages disagree (Lizard Creek 25 or 30 ft, Many Glacier 21 to 35 ft, Mariposa Grove Road 21 or 25 ft) we use the lower figure and say so. Where a park publishes nothing, the row says "not published" instead of guessing. A flag is an instruction to filter by site length on the booking page, not a refusal.
Data last verified 2026-10-28. Prices, hours and rules change; confirm with the official source before you go.
Sources
- NPS Zion: large vehicles and the Zion-Mt. Carmel Highway limits
- NPS Glacier: Going-to-the-Sun Road vehicle size limits
- NPS Yosemite: vehicle restrictions by road
- NPS Yosemite: campgrounds and RV/trailer length limits
- NPS Glacier: camping information (per-campground lengths)
- NPS Grand Teton: camping (length limits by campground)
- NPS Yellowstone: campgrounds table
- NPS Acadia: oversized vehicles and clearances
- NPS Sequoia & Kings Canyon: directions and vehicle length advisories
- NPS Olympic: camping (per-campground lengths)
- NPS Rocky Mountain: camping
- NPS Shenandoah: Marys Rock Tunnel clearance
- Recreation.gov facility pages (linked per row)
Related guides
Frequently asked questions
Which length do I enter: the RV alone or the whole combination?
Both. "Unit length" is the motorhome by itself or the trailer by itself, measured bumper to bumper including the hitch and any rear rack. "Total length" is everything on the road together: motorhome plus towed car, or truck plus trailer. Parks mix the two: Zion limits a single vehicle to 35 ft 9 in and a combination to 50 ft; Gros Ventre and the Colter Bay RV Park quote a combined limit; Yosemite and Mather quote the RV or trailer alone. The tool applies whichever kind of limit each row publishes, and says which one it used.
Why does a campground show "flag" instead of yes or no?
Three reasons. Some parks publish no maximum at all (Zion Watchman, Shenandoah, Flamingo), so we cannot say yes. Some only publish per-site driveway lengths on Recreation.gov (Bryce North, Cades Cove, Fruita), where the longest site may take a 60 ft combination but most take 30, so you fit only if you book the right site. And some campgrounds have a normal limit with a handful of longer sites, such as Olympic's 21 ft rule with a few 35 ft sites. A flag means "possible, but only on specific sites": filter by site length on the booking page.
Does the tool check height and width?
Only where a park publishes a figure. Zion (7 ft 10 in wide, 11 ft 4 in tall), Going-to-the-Sun Road (8 ft wide, 10 ft tall), Acadia's Park Loop Road underpasses (as low as 11 ft 8 in), Shenandoah's Marys Rock Tunnel (12 ft 8 in), Yosemite's El Portal Road (13 ft) and the curb-side clearances of the Wawona and Big Oak Flat tunnels are in the data. Measure to the top of the tallest roof item, and include mirrors in width: the parks do.
The Zion result says my trailer needs a hitch-to-axle measurement. What is that?
Since June 7, 2026 the Zion-Mt. Carmel Highway allows a combination up to 50 ft only if the trailer is no more than 26 ft from the hitch pin or coupler to the centre of its rear axle. That distance is shorter than the trailer's overall length, and it is not printed on a spec sheet, so we cannot compute it. If your trailer is over 26 ft overall the tool flags it; measure with a tape before you plan on the tunnel.
How current are these limits, and should I trust them for booking?
Every figure was read on 28 October 2026 from nps.gov, the Recreation.gov facility API or the park concessioner's page, and each row carries that link. Parks change limits (Zion did in June 2026, Yosemite lowered Mariposa Grove Road to 21 ft in 2026), and Recreation.gov site data is edited constantly. Treat this as a shortlist, open the source link, and confirm the specific site before you pay.