Thunder Mountain

Mendenhall Glacier from Thunder Mountain

6 miles round trip, 3000 feet elevation gain
Difficulty: Strenuous
Access: Free; trailhead can be reached by public transit

Can any other hike claim to combine such easy access from a populated area and such an unparalleled view of a massive glacier? There are certainly none that I know of; at least in the United States, Thunder Mountain may be the only hike that you can reach via public bus that ends with a view over the snaking Mendenhall Glacier descending from the Juneau Icefield as well as the multitude of peaks and islands that make up Southeast Alaska. Thunder Mountain is a tough hike that packs in some extremely steep segments- but for hikers willing to endure mud and switchback-less climbs up the side of a steep Alaskan mountain, expansive meadows and even more expansive views await.

Juneau, Alaska is the most remote state capital in the United States: it is not connected by road to any other part of the country or, for that matter, any other part of Alaska. Getting to Juneau involves a trip by air or water; the town is completely cut off on one side by the tortuous fjords and straits of the Inside Passage and on the side by the icy tongues of the Juneau Icefield. The Mendenhall is one of the many glaciers pouring out from the icefield, snaking 13 miles down a steep valley before terminating at a milky lake; the suburbs of the Mendenhall Valley lie less than three miles away. Thunder Mountain rises above the Mendenhall Valley, providing an unequaled view across the lake to the path of the glacier.

Thunder Mountain isn't only easily accessible by bus; it's also less than an hour's walk from Juneau International Airport. It's possible to get to the Heintzleman Ridge Trailhead for this hike by taking either Bus 3 or 4 (Mendenhall Valley) from either the valley, the airport, or downtown Juneau and getting off at the Alaska Department of Transportation; from the DOT, walk, northwest for 100 yards along Glacier Drive to a construction site parking lot; the Heintzleman Ridge Trail starts from the back of the lot and is labelled with a trail sign. I reached the trailhead by foot from the airport: after flying in on an Alaska Airlines flight from Seattle, I dropped off my bag with Alaska Seaplanes, which provides $5/day luggage storage, and walked out of the airport. I followed Glacier Highway northeast to its junction with Egan Drive; then followed a trail east along Egan Drive until it reconnected with Glacier Highway. From here I continued on to reach the trailhead near the Alaska DOT on Glacier Highway, a little over two miles from the airport.

The trail, marked with pink tape, wasted very little time before becoming a rough, narrow, easy-to-lose route through the Alaskan rain forest. Mud was everywhere, both on the trail and off it, and often the only alternatives to sinking shin deep in mud was to tread on wet, slippery tree roots. After a short period of fairly flat hiking, the trail reached the foot of Thunder Mountain and began a steep climb. Some scrambling was necessary at first up a steep slope filled with tree roots and rocks; soon the trail became a little more reasonably steep but was still covered in mud. Following the pink trail tape, I ascended slowly up a ridge until breaking out into a meadow on a saddle about a mile and a quarter into the hike.

Meadows on the Heintzleman Ridge Trail

The meadow provided a nice change from the tree-covered terrain that I had encountered earlier. However, this part of the hike was particularly muddy, with my boots sinking two inches into the wet meadow surface with each step. A stagnant stream filled the saddle, requiring a running leap to avoid getting soaked to my waist. Past the stream, the trail quickly returned to the forest and resumed climbing up the southwest ridge of Thunder Mountain. The trail was unrelentingly steep, often requiring scrambling up roots or rocks; I was very glad to have bought a pair of hiking poles after arriving in Juneau before beginning my hike.

About half a mile and a few hundred feet of ascent from the meadow, the Heintzleman Ridge Trail merged with the white-blazed Thunder Mountain Trail, which ascended from Jennifer Drive in Mendenhall Valley. From the intersection, I continued an uphill ascent, soon passing a sign informing me that I had entered Tongass National Forest. From here on, the trail began passing through a mixture of forest and meadows, with occasional views of clouds and the glacier through the clouds. Finally, after two hours of uphill slog, the trail broke out of the trees for its first real views of the summit of Thunder Mountain and of Auke Bay and Mendenhall Valley. Just a bit further on, the trail finally broke entirely into the alpine: a final steep climb up the meadows of Thunder Mountain laid ahead and the suburbs of the Mendenhall Valley laid bellow.

Approaching the summit meadows

Tiny blue and yellow flowers dotted the trailside as the path steepened to a nearly 45 degree pitch, tackling the final climb head-on with no switchbacks. After some scrambling, I reached the summit plateau, where the trail leveled off and reached a junction. A cairn marked the path to the left, which headed to the summit of Thunder, while the main trail continued off to the right towards the even steeper terrain of Heintzleman Ridge. I took the left branch, having had enough of mountain goat terrain.

The next half mile of the hike was the most enjoyable: I followed the path along the meadow-filled flat top of Thunder Mountain, passing tarns and lupine filled meadows filled with the whistles of marmots. I made noise to declare my presence to any possible bears, which I had read frequent the summit meadows. Unfortunately, there wasn't much for views at first, as a series of clouds had just rolled in when I reached the summit.

Lupine atop Thunder Mountain

Heintzleman Ridge

Meadows atop Thunder Mountain

Marmot in the meadows

The path grew progressively fainter as it traversed each of the bumps on Thunder Mountain's summit. Soon, the trail came to the massive cliff edge of Thunder Mountain that towered over Mendenhall Valley. Although the better established trail seemed to end here, a barely beaten path continued onward along the bumps that formed the edge of the cliff, heading north to the other edge of the summit plateau. From the north end of the cliffs, I could see straight down to Mendenhall Lake and Mendenhall Glacier; I also spotted Nugget Falls plunging into the lake from this vantage point. The final stretch to reach this point was poorly marked and overgrown; be careful if you choose to hike out to this point, especially if you lose the path, as there are occasionally accidents on the cliffs that form the west face of Thunder Mountain. Appropriately, I spotted a mountain goat atop this mountain that seemed most suited to those animals.

Mountain goat above the subdivisions of Mendenhall Valley

I spent nearly two hours taking in the views at the summit, watching the Mendenhall Glacier and its nearby peaks float in and out of the clouds. At one point, it rained; at other times, it was sunny; usually there were clouds, once there was a rainbow. I saw ravens and a bald eagle, the waters of Auke Bay and the ice of the Mendenhall Glacier. The summit was quiet save the whistles of marmots and the occasional droning from helicopters carrying cruise ship tourists that flew by on their way to the Mendenhall Glacier. The view to the west was quite impressive: I could see the airport and the north end of Douglas Island and farther away I could see a peek of the Lynn Canal and the Chilkat Range, as well as Admiralty Island the mountains out by Gustavus and Glacier Bay. However, the most impressive view was still to the north, where the Mendenhall Glacier snaked down from the Juneau Icefield through imposing mountains, an icy road from a meltwater lake to a frozen plain. The ice of the Mendenhall Glacier was remarkably blue, a feature absent from the smaller glaciers that I often saw in the Washington Cascades.

Foggy lake and glacier

Auke Bay and the Mendenhall Valley

Mendenhall Lake and Glacier

Rainbow on Thunder Mountain

Auke Bay

Glacier detail

After sitting and gazing at the glacier for over two hours, I finally dragged myself from the view and started the return to the trailhead. I found the skies much clearer than during my ascent, when the summit was clouded in: there were now good views of Douglas Island, the Lemon Creek area of Juneau, Gastineau Channel, and the peaks that rose directly behind Juneau itself. The descent was no more easy than the way up; the steepness of the trail made going downhill slow going as well.

Gastineau Channel, Douglas Island, and Lemon Creek

Having had enough of the mud on the Heintzleman Ridge Trail on the way up, I chose to take the Thunder Mountain Trail down to Jennifer Drive on the way back. This trail was quite direct and to the point, wasting no time in dropping down the west side of the mountain. At times, the trail felt more like a root-covered slide. While this trail avoided the mud of the Heintzleman Ridge Trail, the (un)pleasant adventure of slipping down tree roots on a steep slope more than made up for that.

An hour of stumbling and falling later, I finally arrived at the base of the mountain, where I crossed a creek and followed the trail along a set of boardwalks to Jennifer Drive. On my walk out to Mendenhall Loop Road, I turned around and saw the cliffs of the mountain I had just summited.

Thunder Mountain from Glacier View Elementary, Mendenhall Valley

This was an excellent hike, but I can not recommend it for everyone. Unless you're in good shape and have experience following poorly marked trails through very steep terrain, you're better off sticking to some of the easier hikes around Juneau. But if you're up for an adventure, Thunder Mountain is a boatload of fun packed with wildlife and unbelievable views.