Bubble Rock

Bubble Rock is a minivan-sized granite boulder perched near the edge of South Bubble above Jordan Pond. At about 100 tons and minivan-sized, it is Acadia’s best-known and most photographed glacial erratic. The boulder is the quick payoff; from the summit you also get Jordan Pond and the mountains around it. If you have time, continue across the Bubbles for a longer look at the ridge.

For the shorter, gentler climb, start from the small Bubble Rock parking area on Park Loop Road. The combined Bubbles hike is 1.5 miles and takes about 60 to 90 minutes, with views from both North Bubble and South Bubble. The alternative approach from Jordan Pond is steeper and rockier, with scrambling and exposed-feeling sections. If that kind of descent makes you uneasy, go back the way you came, especially when the rocks are wet.

The Park Loop Road lot is small and often fills when the park is busy, so arrive early if you need a space there. There’s no restroom at that trailhead, and no food service up on the hill. Pets are allowed on the Bubbles hike.

The rounded boulder sits against a broad shelf of exposed granite. From the front, it can look as if it might roll away; look at the point where it meets the ledge to see how the rock is actually supported. For a photo, include the granite below it and some of the slope around it. A tight crop loses the setting that makes the boulder look so improbably balanced.

Bubble Rock is made of Lucerne Granite, different from the Cadillac Mountain Granite underfoot around it. A glacier carried the boulder from northwest of Acadia and dropped it as the ice melted. Scraping against the ground wore down its sharper corners, leaving the rounded shape you see on the summit. Its contrasting stone is a clue that this rock traveled here from elsewhere.

North and South Bubble are rounded, asymmetrical granite hills at the north end of Jordan Pond. Glacial ice smoothed their northern sides and quarried the southern slopes, helping give the hills their bubble-like outline. Jordan Pond itself is held back by an end moraine, a ridge of debris left at the front of a glacier. From the summit, you can see the pond and the surrounding mountain landscape that the ice shaped.