Two of the great high-alpine park drives, compared for drivers: season length, vehicle limits, reservation systems, services and which one fits your trip.
Road notes
- Trail Ridge Road is 48 miles one way with a driving time of about 2 hours, climbing to 12,183 feet, the highest continuous paved road in the United States.
- Trail Ridge Road normally opens in the last week of May and closes in mid-October, with an average winter closure date of October 23.
- Going-to-the-Sun Road limits vehicles to 21 feet long and 8 feet wide between Avalanche Creek and Rising Sun; over 10 feet tall risks hitting rock overhangs.
- Rocky Mountain requires timed entry reservations during set hours; Glacier required no vehicle reservations in 2026, but its shuttle runs as a reservation-only express service.
- Check each road’s status with the National Park Service before you go, because weather can close either one at any time.
America has two roads where the drive itself is the reason for the trip: Trail Ridge Road in Rocky Mountain National Park and the Going-to-the-Sun Road, the alpine crossing in Glacier National Park in northwest Montana. Both climb well above the trees, both are buried under snow for much of the year, and both come with rules that can catch an unprepared driver. Here is how they compare, road by road, so you can pick the one that fits your route, your rig and your dates.
The Two Roads at a Glance
| What to compare | Trail Ridge Road | Going-to-the-Sun Road |
|---|---|---|
| The crossing | 48 miles one way, linking Estes Park and Grand Lake | Crosses Logan Pass; restricted section between Avalanche Creek and Rising Sun |
| High point | 12,183 feet, the highest continuous paved road in the country | Logan Pass, with rock overhangs on the west side |
| Typical season | Last week of May through mid-October in a normal year | Shorter and snow-dependent; confirm dates with the park |
| Vehicle limits | None on Trail Ridge; Old Fall River Road bars vehicles over 25 feet and trailers | 21 feet long and 8 feet wide maximum in the restricted section |
| Reservations | Timed entry permit needed 9 a.m. to 2 p.m. in season | No vehicle reservations in 2026; shuttle tickets required for longer hikes from Logan Pass |
| Services | Alpine Visitor Center at 11,796 feet: restrooms, restaurant, gift shop | Sparse services and unreliable cell coverage |
Elevation, Length and Time Behind the Wheel
Trail Ridge Road is the easier one to plan because the numbers are fixed. Colorado’s transportation department lists it at 48 miles with a 2-hour driving time, and the crossing tops out at 12,183 feet before dropping to Grand Lake on the west side. Eleven of those miles sit above 11,500 feet, with few guardrails and no shoulders, so the 2-hour figure assumes you are moving. In practice you will stop often at the overlooks and short trails along the route, and elk, bighorn sheep and deer show up on the meadows regularly enough that you should budget extra time. The road has held All-American Road status, the top national scenic byway designation, since 1996.
The Going-to-the-Sun Road is a slower, tighter drive where it counts. Between Avalanche Creek and Rising Sun the lanes are narrow, the curves are sharp, and rock overhangs loom above the west side of Logan Pass. One comfort note for first-timers: drivers report that heading east to west, starting near St. Mary, keeps you on the rock-wall side instead of the drop-off side, which helps if heights bother you. Our guide to driving in national parks for beginners covers the low speeds and pullout habits both roads demand.
When Each Road Opens and Closes
Trail Ridge Road has a predictable shape to its year. Plow operators start clearing snow in mid-April, with crews from both sides of the park meeting at the Alpine Visitor Center. Through travel normally resumes during the last week of May: the 2025 opening came on May 30, the earliest on record was May 7, 2002, and the latest was June 26, 1943. The average winter closure date is October 23, though the 2025 season ran until November 14. Temporary closures can take effect at any time, and the park warns of sun, strong winds, blowing snow and ice year-round. Even with the pass shut, short sections stay drivable, including the road to Hidden Valley and Many Parks Curve on the east side.
The Going-to-the-Sun Road opens later, and its dates shift with the snowpack each season, so check the park’s status page before booking anything. Our checklist for before you drive Going-to-the-Sun Road covers what to verify, and if your trip falls in the colder months, our guide to winter mountain driving explains traction rules and how closures work.
Vehicle Length and Width Limits
This is the biggest practical difference between the two roads. On the Going-to-the-Sun Road, vehicles longer than 21 feet or wider than 8 feet are not allowed between Avalanche Creek and Rising Sun, where the lanes narrow and the curves tighten. Anything over 10 feet tall also risks clipping the rock outcrops that overhang the west side of Logan Pass. If your vehicle exceeds those numbers, the common workarounds are renting a car for the day or riding the park shuttle.
Trail Ridge Road has no published length or width limit for the main crossing, and RVs and trailers are common in summer. The strict limit in Rocky Mountain applies to Old Fall River Road, the unpaved one-way route to the Alpine Visitor Center, where vehicles over 25 feet and anything towing a trailer are barred. Measure your vehicle at home, bumpers included, and check each park’s vehicle page before you go.
Timed Entry, Reservations and Crowd Patterns
Rocky Mountain runs a timed entry system in 2026, from May 22 into mid-October. The basic Timed Entry permit, the one that covers Trail Ridge Road, is required each day from 9 a.m. to 2 p.m.; a separate Timed Entry + Bear Lake Road permit, in force 5 a.m. to 6 p.m., adds the busy Bear Lake corridor. Permits go on sale on Recreation.gov in monthly batches at 8 a.m. Mountain Time, with a second batch at 7 p.m. the night before each date. The reservation costs $2 on top of the park entrance fee and gives you a two-hour arrival window. Without one, you can still drive in outside those hours, before 9 a.m. or after 2 p.m.
Glacier took the opposite approach in 2026: no vehicle reservations at all, so you can drive in at any hour. The tradeoff comes at Logan Pass, where the lot fills by mid to late morning in peak season and parking is capped at 3 hours. Starting July 1, 2026, the park shuttle operates as a reservation-only express service; each rider age 2 or older buys a $1 ticket on Recreation.gov. Longer hikes from the pass require a pre-booked shuttle ticket, and overnight parking there is off limits except for backcountry permit holders and Granite Park Chalet guests.
Road-tested tip
For Trail Ridge Road conditions, call the park’s recorded status line at 970-586-1222, which is updated whenever the road status changes. Weather can close the pass even in July.
Fuel, Food and Services Along Each Route
Trail Ridge Road has one genuine service stop: the Alpine Visitor Center at Fall River Pass. At 11,796 feet it is the highest visitor center in the National Park Service, and it has restrooms, a restaurant and a gift shop. Fill the tank in Estes Park or Grand Lake first, since those towns bookend the drive.
The Going-to-the-Sun Road is leaner. Cell coverage is unreliable across the park, so download maps, save shuttle tickets offline and fuel up before the entrance. Plan the day around parking and shuttle rules rather than expecting services along the way.
Which One Fits Your Trip
Trail Ridge Road suits drivers who want a classic alpine crossing with minimal logistics: a standard car works, the drive takes about 2 hours, there is food and a restroom at the top, and shifting your arrival time sidesteps the permit. It also fits RVs, as long as you skip Old Fall River Road.
Going-to-the-Sun Road suits travelers already headed to northwest Montana who are comfortable with shuttle tickets and parking limits and who drive something under 21 feet. It is the better pick for hikers, since the shuttle connects trailheads on both sides of Logan Pass. Neither road is universally better; the right one depends on your rig, your dates and how much paperwork you want. For fuel costs on the drive to either park, see our road trip fuel math, and if Glacier wins, our pre-drive checklist for Going-to-the-Sun Road walks through what to verify before you go.
Questions from the road
Q: Which road has a longer driving season?
A: Trail Ridge Road normally opens in the last week of May and closes in mid-October, so you can plan around those dates. The Going-to-the-Sun Road season depends on snow clearing each year, so confirm current dates on the park’s website before booking anything.
Q: Can I drive either road in an RV or a truck towing a trailer?
A: Trail Ridge Road itself has no published length limit, though vehicles over 25 feet and anything pulling a trailer are barred from the Old Fall River Road side route. On the Going-to-the-Sun Road, vehicles longer than 21 feet or wider than 8 feet are prohibited between Avalanche Creek and Rising Sun.
Q: Do I need a reservation to drive these roads?
A: Rocky Mountain National Park requires a timed entry reservation during certain hours, including a 9 a.m. to 2 p.m. window for areas such as Trail Ridge Road; arriving outside that window gets you in without a permit. Glacier did not require vehicle reservations in 2026, but its park shuttle became a reservation-only service, and longer hikes from Logan Pass require a pre-reserved shuttle ticket.
Q: Which direction should I drive the Going-to-the-Sun Road?
A: Heading east to west from St. Mary puts the rock wall on your side and the drop-offs away from the driver, which many drivers with a fear of heights prefer. Confirm current conditions with the park before you choose.
Road rules, fees, closures and border requirements change. Check with the state transportation department, park, rental company or border agency before you travel. This guide is general information.
