The Park Loop Road & Getting Around
Twenty-seven miles along the top of granite sea cliffs, taking in almost everything you pictured when you pictured Acadia. Here is how to drive it well — or skip the car entirely.
The best road in the park, and it asks almost nothing of you.
This is the drive that sells Acadia. Twenty-seven miles of it, running along the edge of the Atlantic past a sand beach wedged into pink granite, cliffs dropping a hundred feet into the water, and a pond with two perfect hills at the end of it. You can do the whole circuit in a morning.
The Park Loop Road needs no reservation at any time — that applies only to Cadillac Summit Road. What it needs is an early start, because Sand Beach parking and the right-hand lane toward Otter Point are routinely full by 9 AM in summer and at weekends.
Much of the loop is one-way. Overshoot a parking area and you are driving the whole circuit again before you get another attempt.
Or park once and ride the Island Explorer, which is fare-free and reaches most of what you came for.
Twenty-Seven Miles, Mostly One Way
What it connects, and the bit that catches people out
The Park Loop Road is Acadia’s spine on Mount Desert Island — 27 miles linking Hulls Cove, Sand Beach, Thunder Hole, Otter Cliffs, Jordan Pond and the turning for Cadillac.
What makes it unusual is how little distance separates things that look nothing alike. You go from a beach to a hundred-foot cliff to a glacial pond in under half an hour, and the road stays close enough to the water that the Atlantic is doing something different at every pullout.
The section from Sand Beach toward Otter Point, often called Ocean Drive, includes the one-way stretch. The park’s own advice is to understand the traffic flow before you set off, and the reason is practical rather than cosmetic: there is no turning back.
Parking fills before most people have had breakfast
Sand Beach and the right lane toward Otter Point can be full by 9 AM in summer and at weekends. The right-hand lane doubles as roadside parking along Ocean Drive, which is why it disappears so fast.
If you are driving yourself, be on the road by eight. It is the single highest-value hour in an Acadia day.
July and August are genuinely congested
The park describes the Park Loop Road as extremely congested in those two months. That is not a crowd-averse traveler’s opinion — it is the park’s own word, and it changes how you should plan the day rather than whether you should come.
It is seasonal, and winter is a short stub
The paved park roads open around April 15. In winter only a limited portion stays open to vehicles — broadly from the entrance station to Otter Cliff Road — so a December visit is a different park, not a quieter version of the same one.
Look before you cross
If you park in the right-hand lane on Ocean Drive, you are getting out of the car into a live traffic lane and crossing to reach the shore. The park says it plainly, and it is worth repeating because the view is on the other side.
📍 The loop needs no reservation. One road inside it does.
People conflate these constantly. Cadillac Summit Road requires a $6 vehicle reservation in season. Everything else — the entire Park Loop Road, every trailhead, Jordan Pond, the carriage roads — requires nothing but an entrance pass.
How the Cadillac reservation works, including the two release drops and four ways up without one.
Acadia Without a Car Actually Works
Which is not true of most national parks
The Island Explorer is fare-free and propane-powered, and it serves campgrounds, trailheads, carriage road entrances, the surrounding towns and the Bar Harbor–Hancock County airport. You can flag one down anywhere it is safe to stop.
You still need a park entrance pass — the bus is free, the park is not.
For a first visit based in Bar Harbor, a car-free trip is genuinely workable: the shuttle reaches the Park Loop Road stops, Bar Island is a walk from downtown, and the Bicycle Express van runs between Bar Harbor and the Eagle Lake carriage road entrance with a bike trailer.
The west side. Trailheads outside the frequent routes are hard to reach.
Schoodic on a tight schedule. The mainland section is about an hour by car, or a seasonal ferry from Bar Harbor to Winter Harbor.
Anything outside the season. The shuttle stops running and the island becomes a driving park again.
Cadillac. The Island Explorer does not serve the summit. No exceptions, no workaround.
The Bicycle Express trailer does not carry dogs. If you were planning to take the bike and the dog to the carriage roads in one trip, that is two trips.
2026 shuttle season
The Island Explorer ran seven days a week through October 13, 2026, with reduced autumn service beginning August 18.
Dates shift year to year and routes are added or dropped. Check the current season before planning a car-free trip around it — this is the one assumption that turns a relaxed visit into a stranded one.
How to actually drive it
Go clockwise from Hulls Cove, which is the direction the one-way sections run.
Stop at Sand Beach first, before 9 AM, because it is the parking that goes earliest.
Treat Thunder Hole as tide-dependent rather than a scheduled stop — it is on the route, so you can check it in passing and come back at the right hour.
Leave Jordan Pond for the afternoon. Its lot holds up better than Sand Beach and the light on the Bubbles improves later.
Practical Notes
- No reservation for the Park Loop Road, ever. Only Cadillac Summit Road, and only in season.
- Entrance pass: $35 per private vehicle for seven days, $30 motorcycle, $20 on foot or by bike. The park is cashless.
- Paved roads open around April 15; in winter only the entrance station to Otter Cliff Road stays open to vehicles.
- The right-hand lane on Ocean Drive is parking — which is why it fills, and why you cross traffic to reach the shore.
- The shuttle is free, the park is not. Riders still need an entrance pass.
- Cell service is patchy; download maps and the shuttle schedule before you set out.
Getting Around Acadia FAQ
Do I need a reservation for the Park Loop Road?
No. The Park Loop Road needs no reservation at any time of year. A vehicle reservation is required only to drive Cadillac Summit Road, and only during the season. You do need a park entrance pass for either.
How long is the Park Loop Road?
27 miles. It links the Hulls Cove Visitor Center, Sand Beach, Thunder Hole, Otter Cliffs, Jordan Pond and the turning for Cadillac Summit Road, and much of it is one way.
What time does Sand Beach parking fill up?
The National Park Service says the Sand Beach lot and the right-hand lane of the Park Loop Road toward Otter Point can routinely fill by 9 AM in summer and at weekends. Be on the road by eight if you are driving yourself.
Is the Island Explorer free?
Yes, it is a fare-free shuttle. You still need a park entrance pass to enter Acadia, but the bus itself costs nothing.
Can you visit Acadia without a car?
More easily than most national parks. The Island Explorer serves trailheads, carriage road entrances, campgrounds, the towns and the airport, and Bar Island is walkable from downtown Bar Harbor. The limits are the west side, Schoodic on a tight schedule, anything outside the shuttle season, and Cadillac — which the shuttle does not serve.
Does the Island Explorer go up Cadillac Mountain?
No. Island Explorer buses do not serve the summit of Cadillac Mountain. To reach the top you either drive with a vehicle reservation, hike up the North Ridge or South Ridge trails, cycle, or take a taxi.
When is the Park Loop Road open?
Paved park roads open around April 15. In winter only a limited section stays open to vehicles, broadly from the entrance station to Otter Cliff Road.
Can I take my dog on the Island Explorer?
The Bicycle Express trailer, which runs between downtown Bar Harbor and the Eagle Lake carriage road entrance, does not carry dogs. Check current policy for the regular buses before relying on one with a dog in tow.
Planning the rest of the trip?
The 3-day Acadia itinerary — the loop as a day, plus a free printable PDF and the map.
Acadia tides — why Thunder Hole is a tide stop, not a scheduled one.
The best hikes in Acadia — which trailheads the shuttle reaches.