This trail wasn’t even on our radar when we arrived on Isle au Haut. Why not? Simply because it’s not on any maps, so we didn’t know about it. I did find it on a USGS topo map, but it’s not on any published park maps. The trail is maintained occasionally, but it’s off the beaten path and takes time to get to. The trail is 1.8 miles out-and-back from the trailhead, but it takes 2.4 miles along an unpaved road to get to from Duck Harbor Campground.

One of the park rangers suggested this hike since we’d be staying on the island for 3 nights, and might have time to hike it. We handed her our printed Isle au Haut map, and she drew it in for us. The end point of the trail was the titular Thunder Gulch, a narrow ravine on the south coast of the peninsula. It’s so named because of the sound of the waves crashing into the gulch at high tides sounds like Thunder. It’s similar to Thunder Hole on Mount Desert Island, which we visited while walking along Ocean Path trail.

To the Trailhead

The trailhead is located on the Eastern Head peninsula, on the southeast coast of Isle au Haut. We knew we wanted to hike it, but also knew that it’s a long way from the campground to the trailhead, mainly along the unpaved Main Road. The road leads out of the park through a rural residential area, and eventually you’ll turn right down another road onto Eastern Head Peninsula where the trailhead is located. You’ll get back onto National Park land shortly after passing through some privately-owned land.

Knowing we had a long hike ahead of us, we left as early as we could and started hiking the road to the trailhead. Not surprisingly, the road is not an interesting hike. Fortunately for us, when we were approaching the main road, a pick-up truck pulled up beside us. It was two of our park ranger buddies, who asked if we wanted a ride to the trailhead! K and I looked at each other, unsure if we should skip the experience of hiking the road. Thankfully, we said yes, and piled into the back of the pick-up. It was great luck, and we saved a lot of time.

We knew we were getting close when we passed a very homemade-looking parking sign for Thunder Gulch. We drove past a few quaint private residences, and soon we were delivered right to the trailhead – which had another unique sign directing us to the trail (see featured photo). We waved our goodbyes, thanked the rangers, and headed to the trail.

Thunder Gulch Trail

The opening view from the trailhead is pretty spectacular, with a great cove next to it. As we started hiking, we left the ocean behind and starting hiking inland, through the middle of the peninsula. There were downed trees everywhere, and the existing trees struggle to get very tall due to the wind. Compared to other places we went on the island, Eastern Head is more exposed with some wide open spaces. It made for a nice change of pace.

The trail is fairly well marked, and there are some blazes, but it’s not as easy to follow as other trails on the island. There are also a couple side paths which we explored – we didn’t find anything amazing though, typically just a path to the coast. We expected to not run into anyone else on this hike, but we ran into two other groups. They weren’t staying at the campground, so they must have been locals or staying somewhere else on the island.

It wasn’t long before we reached the coast, and Thunder Gulch. It wasn’t high tide, it was somewhere between low and high, but we hadn’t really thought about timing the tides. As a result, while there was a definite “thunder” to the waves, the sound wasn’t amazing. But altogether, the sound, ravine, coast, and hike were a great experience. We got as close to the ravine as we could, and scrambled around on nearby rocks, making sure to watch our footing.

After exploring the gulch, we went along the coast for a short walk. We climbed a huge boulder, and took a quick power nap on top of it. When we opened our eyes, a thick fog had rolled in. And – we think – it had only been 5 minutes! That was our cue to head back the way we came. It’s a quick hike, but once we got back to the Thunder Gulch trailhead, we had a long walk on Main Road back to the campground.

On the hike back, we also did a quick 1.1 mile loop of the Goat Trail, since I had heard there were some carnivorous plants and orchids there. We had seen some on the way to Isle au Haut Town, but what we found on the Goat Trail was better: there is a boardwalk to get you closer to the plants, which made for good photo ops. Closer to the campground, we also took a quick 0.7 mile hike on Eben’s Head Trail, the big rock outcropping in Duck Harbor. We were exhausted at this point, but this was our last day, so we wanted to see it. It was nice, but very windy on top of Eben’s Head.

Thunder Gulch is a very nice trail, and if you have the time, I would recommend it. There are better trails on the island, but it’s still very rewarding. Why is it not on any maps? We asked the park ranger when we boarded the mail boat to leave Isle au Haut. And the answer is simply because the trail is surrounded by a residential area. Keep that in mind if you decide to hike the trail. Be respectful of private property and leave no trace!

Thunder Gulch Trail
Distance: 1.8 miles / 2.9 kilometers roundtrip
Type: Out and back
Elevation Gain: 292 feet / 89 meters
Difficulty: Easy
Crowds: None.  We saw a few groups of people (surprisingly!), but it wasn’t crowded.
Water: Oceans, but we didn’t see any type of fresh water.
Parking: In Stonington, most likely
Directions to Trailhead From Duck Harbor Campground (Google Maps Directions):

• Mile 0.0 – First head east on the gravel service road that heads inland. You’ll pass the intersection with Western Head Road in 0.1 miles, then you’ll pass the water pump.
• Mile 0.4 – Turn right onto Main Road, and head southeast for 1.8 miles.
• Mile 2.2 – At this point, there is a small parking sign for Thunder Gulch. Turn right onto Head Harbor Road.
• Mile 2.4 – You’ve arrived! The trailhead will be on your right.

Trail Directions: 

• Mile 0.0 – Head south on the Thunder Gulch Trail. You’ll have the coast and a nice cove on your right. The first part of the hike goes through private property, so be respectful.
• Mile 0.4 – An optional side trail to the right goes to a rocky beach. Otherwise, continue on the main trail.
• Mile 0.9 – Arrive at Thunder Gulch! Enjoy, relax, and hear the waves crashing on the rocks, and then head back the same way you came.
• Mile 1.8 – Back at the trailhead, and time for the hike back to camp. Why not explore Goat Trail or Eben’s Head too?

Highlights: Views, rocky shorelines, windswept area, off the beaten path trail, the “thunder” from the gulch, different from other hikes on the island
Notes: The total mileage round-trip, with the trail and hiking from Duck Harbor, is around 6.6 miles.

Places:
Duck Harbor Campground | 44.028130, -68.652953
Thunder Gulch Trailhead | 44.022208, -68.616721
Thunder Gulch | 44.011720, -68.14373
Goat Trailhead | 44.023059, -68.632114
Eben’s Head Trailhead | 44.030190, -68.651430

References:
Thunder Gulch Trail Map (KTNPBlog)
Isle au Haut Map (KTNPBlog)
Isle au Haut Map (NPS)