Glacier National Park RV Size Limits on Going-to-the-Sun Road

Last updated October 28, 2026 · By RV National Parks Guide Editorial Team

The rule on Going-to-the-Sun Road is the tightest in the national park system: nothing longer than 21 feet including bumpers, or wider than 8 feet including mirrors, between Avalanche Creek and Rising Sun. The NPS also posts a 10-foot height figure and warns that taller vehicles can have trouble with the rock overhangs heading west from Logan Pass to The Loop. That excludes every Class A and Class C, every travel trailer and fifth wheel, and most Class B vans once you add the mirrors.

The alpine section is the only part of the park with a size limit. Both ends of the road, West Glacier to Avalanche and St. Mary to Rising Sun, take any legal vehicle, and the roads to Many Glacier and Two Medicine have no posted size restriction. So the RV plan for Glacier is to camp low, in a campground whose pads fit your rig, and go over the pass by shuttle, tow vehicle or rental car. This guide gives the exact limits and where they apply, the per-campground site lengths from the NPS camping information page, the 2026 Logan Pass parking and shuttle rules, and how to time a visit around a road that may not open until late June. Sources are the NPS Going-to-the-Sun Road information page, the NPS camping information page, the park’s 2026 Logan Pass page and Recreation.gov, read in October 2026.

The limit and exactly where it applies

The NPS release announcing the road’s full opening on June 22, 2026 used identical wording, so the rule has not changed. The sections not covered:

• West side: West Glacier entrance, Apgar, the length of Lake McDonald, Lake McDonald Lodge, Sprague Creek and Avalanche. Any rig that fits a campsite can drive this far.
• East side: St. Mary entrance to Rising Sun, about six miles.
• Elsewhere in the park: the Many Glacier road from Babb, the Two Medicine road from East Glacier, and US-2 around the south boundary between West Glacier and East Glacier carry no NPS size restriction. US-2 is the route a big rig takes to get from one side of the park to the other, about 1.5 to 2 hours.

Why 21 feet and 8 feet: the alpine section is a 1930s two-lane road with stone guard walls, overhanging rock at several points, tunnels cut through the mountainside and tight curves where a long vehicle cannot stay in its lane. Even vehicles that meet the limit must fold in mirrors at some points and will scrape the uphill wall if they drift.

Does your rig qualify?

Almost certainly not, if it is anything other than a van or a small truck camper. Measure before you argue with the sign:

• Class B vans: many are 19 to 22 feet long and 6 ft 8 in to 7 ft 4 in wide at the body. The mirrors add 10 to 16 inches a side. A Sprinter 144 is under 20 feet and about 7 ft 10 in to 8 ft 4 in mirror to mirror depending on the mirrors fitted; a 170 wheelbase is over 22 feet. Measure yours.
• Truck campers: a crew-cab short-bed pickup is 19 to 20 feet, and a camper that overhangs the tailgate pushes it past 21. Width with towing mirrors is usually over 8 feet; with standard mirrors it is close. Height with the camper is 10 to 12 feet, into the advisory zone.
• Anything towing anything: the 21 feet applies to the combination. A car pulling a teardrop can qualify; a pickup pulling a 16-foot trailer cannot.
• Class C, Class A, travel trailer, fifth wheel: over on length and width. No exceptions, no permit, no escort.

If you are under the limit, you still need somewhere to park at the top. In 2026 that came with a clock.

Logan Pass in 2026: no vehicle reservation, a three-hour clock, a ticketed shuttle

The NPS states that vehicle reservations are not required in 2026 anywhere in the park, ending the timed-entry system of previous summers. In its place the park ran a pilot at Logan Pass from July 1 to September 7, 2026:

• Three-hour parking limit for private vehicles, enforced 24 hours a day, with a free time-stamped permit from a kiosk displayed on the dash. No overnight parking except for backcountry permit holders and Granite Park Chalet guests.
• A ticket-only Logan Pass shuttle boarding at Apgar Visitor Center, Lake McDonald Lodge, St. Mary Visitor Center and Rising Sun picnic area. Tickets were sold only on Recreation.gov, not in the park, for a $1 non-refundable processing fee per person; children two and over needed their own ticket. A 60-day rolling window opened May 2, 2026 at 8 am Mountain, with remaining tickets released at 7 pm the day before from June 30. The shuttle did not serve Avalanche Lake or Trail of the Cedars and did not run past Labor Day.

For an RVer this is good news: no entry reservation to chase, and a shuttle that leaves from the two campgrounds most big rigs use, Apgar and St. Mary. The 2027 arrangements had not been published as of October 2026; the park’s vehicle reservations page is where the announcement will land, usually in February. Timed entry at other parks is covered in the general national park timed entry guide.

Campgrounds: how many sites fit which length

Glacier publishes site counts by length rather than a single campground maximum, which is unusually useful. From the NPS camping information page, October 2026:

Fees: the NPS gives a summer range of $15 to $30 per night rather than a per-campground figure; hiker-biker sites are $8 per person; no refunds. Maximum stay is 14 days from July 1 to Labor Day and 30 days otherwise. Quiet hours are 10 pm to 6 am, eight people and two vehicles per site, check-out at noon. Shared water spigots and flush toilets are seasonal; there are no hookups anywhere in the park.

Practical reading: a rig up to 40 feet has 28 sites in the whole park (25 at Apgar, 3 at St. Mary). A 35-footer adds Fish Creek’s 18, St. Mary’s 22, Many Glacier’s 13 and Two Medicine’s 10. Everything else is a 26-foot-and-under campground. If you are over 40 feet, or want hookups, you are camping in West Glacier, Columbia Falls, St. Mary or Babb and driving in. The hookups-in-national-parks list shows how unusual Glacier’s zero is.

Booking a site

Eight of the 13 front-country campgrounds are reservation-only on Recreation.gov. The park’s wording is that most sites have a six-month booking window and “a good handful” have a four-day window, so there are two chances at each campground: the morning six months before your date, and again four days out when the short-window sites release. St. Mary switches to a day-of window from August 17 to September 11. The NPS warns that cell service inside the park is unreliable, so make the four-day and day-of bookings from West Glacier or St. Mary village, not from a campsite. Our Recreation.gov guide for RVers covers the length filter, which matters more here than almost anywhere, because a “35-foot” campground has a dozen such sites among a hundred shorter ones.

The park entrance fee is $35 per vehicle for seven days and the America the Beautiful pass covers it; the pass does not cover the $1 shuttle ticket fee.

A plan that works for a big rig

1. Camp west at Apgar or Fish Creek for two or three nights. Both have dump stations and sit at the foot of Lake McDonald, with the Apgar shuttle stop a short walk or bike ride away. Drive your tow vehicle, or ride the shuttle, up to Logan Pass; if you drive, be back under the three-hour limit.
2. Move the rig around the south of the park on US-2 to the east side, 1.5 to 2 hours West Glacier to St. Mary via East Glacier. No size restriction.
3. Camp east at St. Mary (40- and 35-foot sites, dump station, the east-side shuttle stop) and day-trip to Many Glacier and Two Medicine in the tow vehicle. If your rig is 35 feet or under and you want to wake up at Many Glacier, book one of its 13 larger sites the morning the window opens and read the pad length twice.

With a van under the limit, the plan simplifies: camp at Avalanche or Rising Sun and drive the road early, before the Logan Pass lot fills, with a shuttle ticket as insurance.

Mistakes to avoid

• Treating 21 feet as the length of the trailer. It is the length of the whole combination, bumper to bumper.
• Assuming the road is open in June. It opened June 22 in 2026 and has opened in July in heavy snow years. Book campsites for the second half of July onward if driving the pass is the point of the trip.
• Booking Many Glacier on the NPS 35-foot figure without reading the site. Recreation.gov describes most pads as too small for a towed unit over 21 feet. The 13 larger sites exist; the other 90-odd do not fit you.
• Planning generator time at Sprague Creek or Cut Bank, or in the no-generator loops at Fish Creek, St. Mary, Many Glacier, Two Medicine and Rising Sun. The allowed windows elsewhere total six hours a day; the sister site’s boondocking primer is relevant here even though you are in a campground.
• Arriving on the east side with full tanks and no plan. St. Mary, Many Glacier and Rising Sun have dump stations; Two Medicine, Sprague Creek and Avalanche are not listed as having one.
• Parking a van at Logan Pass for a Highline Trail day. Three hours, enforced around the clock, in 2026. Take the shuttle for long hikes.

When to go and how long

The alpine road is reliably open from early July to late September, and the third Monday of October is the typical end. July has the wildflowers and the worst parking; September has cooler nights, fewer people and the first snow on the pass by month’s end. Four nights, two per side, is the minimum to see Lake McDonald, Logan Pass, Many Glacier and Two Medicine without a five-hour day in the tow vehicle. For how Glacier’s rule compares with Zion’s new 35 ft 9 in limit and Yosemite’s tunnel heights, see the Zion RV size limits guide and our national park RV size limits roundup.