Ptarmigan Tunnel: One of Glacier National Park's Best Hikes

For hikers searching for one of the most unique adventures in Glacier National Park, the Ptarmigan Tunnel Trail belongs near the top of the list. Beginning in the Many Glacier area, the spectacular hike climbs through forests and wildflower-filled meadows before reaching Ptarmigan Lake, then tackles a dramatic series of switchbacks to a 250-foot tunnel blasted directly through the Ptarmigan Wall. Emerging from the opposite side reveals an entirely different landscape overlooking the remote Belly River country, making hiking to Ptarmigan Tunnel one of the best day hikes in Glacier National Park.

Trailhead elevation 4,961'

Water filterable from Ptarmigan Lake

Don't miss the view of Old Sun Glacier on the north side of the tunnel

Hiking Swiftcurrent Mountain Lookout

The hike begins from the Iceberg-Ptarmigan Trailhead near Swiftcurrent Motor Inn at the end of the Many Glacier Road. The National Park Service lists this as the trailhead for both Iceberg Lake and Ptarmigan Tunnel, with a nearly 200 vehicle parking area available beside the motor inn. Although large, the lot tends to fill to capacity by 7:00 AM during the park's busy season (July through Labor Day).

From the trailhead, hikers immediately begin climbing away from the Swiftcurrent Valley on the shared Iceberg Lake–Ptarmigan Tunnel Trail, gaining elevation along the lower slopes of Mount Henkel. The opening portion of the hike travels primarily through forest, but breaks in the trees provide increasingly impressive views across the Many Glacier Valley. To the east, Mount Wilbur, Mount Grinnell, and Swiftcurrent Mountain rise prominently above the surrounding landscape, while the broad Swiftcurrent Valley stretches toward the heart of Many Glacier.

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This lower portion of the trail is also prime wildlife country, and hikers should remain alert for black bears, grizzly bears, moose, deer, and other wildlife throughout the hike.

As the trail steadily gains elevation, the forest occasionally gives way to more open slopes and meadows, particularly beautiful during Glacier National Park's summer wildflower season. The scenery becomes progressively more mountainous with each passing mile, and the transition from the developed Many Glacier valley into Glacier's rugged backcountry happens surprisingly quickly. Before long, the trees begin to open up, revealing stunning views of Mount Grinnell, Mount Gould, and the towering Ptarmigan Wall. For a brief stretch, hikers are also treated to an exceptional view into Swiftcurrent Valley, including its dramatic headwall and Swiftcurrent Glacier—scenery that can be experienced up close along the ultra impressive Swiftcurrent Mountain Lookout Trail.

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Roughly 2.8 miles from the trailhead, hikers approach Ptarmigan Falls, where Ptarmigan Creek tumbles through a narrow gorge beneath the trail. Although trees obscure portions of the waterfall, the rushing water makes this a popular stopping point and a natural place to take a break before the hike becomes more demanding.

Just beyond this area, hikers arrive at the most important junction of the hike. The heavily traveled trail continuing west leads toward Iceberg Lake, while the Ptarmigan Tunnel Trail turns north and begins climbing into the Ptarmigan Creek drainage. Most hikers heading toward Iceberg Lake disappear at this junction, and the character of the hike changes almost immediately. The Ptarmigan Tunnel route generally feels quieter, wilder, and more remote from this point forward. The trail climbs steadily through forest along the western side of the Ptarmigan Creek valley before eventually emerging into increasingly open terrain.

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Around the three-mile mark, the trees begin thinning enough to reveal the enormous Ptarmigan Wall rising along the western side of the valley. Across the drainage, Crowfeet Mountain, which rises to roughly 8,900 feet, forms the valley's imposing eastern wall.

This middle portion of the hike is one of its most beautiful stretches. The trail passes through lush meadows broken by scattered stands of conifers, with wildflowers covering the slopes during the heart of summer. The terrain feels increasingly alpine, and hikers who turn around will find excellent views back toward Mount Wilbur and Mount Grinnell, two of the most recognizable peaks in the Many Glacier area.

The geology becomes increasingly noticeable as well. Much of Glacier National Park consists of ancient sedimentary rock originally deposited in the Belt Sea more than a billion years ago before being uplifted and sculpted by glaciers. The distinctive reddish rock surrounding Ptarmigan Tunnel belongs to the Grinnell Formation, and the tunnel itself was drilled directly through this ancient formation. The colorful bands of red, green, gray, and brown rock help give the Ptarmigan Wall its striking appearance.

As hikers approach Ptarmigan Lake, the valley tightens dramatically. Forest gives way to low alpine vegetation, talus, and increasingly barren rock as the trail approaches the base of the Ptarmigan Wall. The surrounding mountains rise almost vertically from the valley floor, creating a classic glacial cirque that feels considerably more rugged than the forested terrain encountered earlier in the hike.

At roughly 4.3 miles from the trailhead, hikers reach Ptarmigan Lake, sitting beneath the sheer cliffs of the Ptarmigan Wall and Crowfeet Mountain. The lake's blue-green water contrasts beautifully with the reddish cliffs, gray talus slopes, and patches of lingering snow surrounding the basin. Ptarmigan Lake is a worthy hiking destination on its own, but the most dramatic portion of the trail is still ahead.

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Looking beyond the lake, hikers can clearly see the route climbing the seemingly impassable headwall. The trail begins ascending the steep talus slopes above Ptarmigan Lake through a long series of switchbacks etched into the mountainside. From below, the trail can look intimidating, but the switchbacks keep the grade manageable as hikers steadily climb toward the tunnel.

The landscape changes almost completely during this final ascent. Trees disappear, vegetation becomes sparse, and hikers enter a world dominated by broken rock, scree, cliffs, and alpine wildflowers clinging to the slopes. There is little protection from the sun, wind, or rapidly changing mountain weather, making this section feel far more exposed than the earlier miles through the forest.

With each switchback, the views over Ptarmigan Lake become increasingly spectacular. The lake shrinks beneath the towering walls of its cirque while Crowfeet Mountain dominates the eastern side of the valley. Farther south, the mountains surrounding Many Glacier begin stacking against the horizon, creating one of the best high-elevation panoramas along the hike.

Eventually, after roughly 5.3 miles and 2,300 feet of elevation gain, hikers reach the southern entrance of Ptarmigan Tunnel. Large iron doors mark the entrance to what is easily one of the most unusual hiking features anywhere in Glacier National Park.

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The Ptarmigan Tunnel was constructed in 1930 to provide a more practical connection between the Many Glacier area and the Belly River country north of the Ptarmigan Wall. Contractor Ole Westman and his crew began work on July 27, 1930, drilling from opposite sides of the mountain with jackhammers and using repeated rounds of dynamite. Less than three months later, the two crews met inside the mountain and completed the approximately 250-foot-long tunnel on September 30.

The engineering achievement was significant enough that Ptarmigan Tunnel was later added to the National Register of Historic Places. It remains the only trail tunnel in Glacier National Park and represents an era when the National Park Service was developing an extensive network of backcountry trails designed to carry hikers and horseback travelers deep into the park.

Walking through the tunnel is an experience unlike anything else on the trail. Natural rock forms the walls and ceiling, and the interior quickly becomes dark and noticeably cooler than the sun-exposed slopes outside. The opening at the opposite end gradually grows larger until hikers emerge through the northern portal. And that is when the hike delivers its biggest surprise.

Passing through Ptarmigan Tunnel feels like stepping into an entirely different section of Glacier National Park. The lush Many Glacier landscape and Ptarmigan Lake disappear behind the mountain, replaced by an enormous view over the Belly River Valley, Elizabeth Lake, the remote northern wilderness of the park, and Canada.

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Hikers should continue at least a short distance beyond the northern entrance rather than immediately turning around. The trail traverses beneath the towering cliffs of the Ptarmigan Wall, providing increasingly expansive views over the Belly River drainage and distant views of 10,004-foot Mount Merritt, one of Glacier National Park's six peaks over 10,000 feet. Clinging to the mountain's massive eastern slopes is Old Sun Glacier, a remnant alpine glacier tucked beneath Mount Merritt's towering summit. Even a few hundred feet beyond the tunnel can provide a different perspective of the valley and the immense mountains surrounding it.

This side of the tunnel also makes it easier to appreciate why the passage was constructed in the first place. Before the tunnel, crossing this enormous rock barrier required a much more difficult route. Blasting a passage directly through the Ptarmigan Wall created a practical connection between Many Glacier and the Belly River country and became an important piece of Glacier's historic backcountry trail network.

After exploring the north side, hikers can walk back through the tunnel and begin the long descent toward Many Glacier. The return trip provides some of the hike's best scenery, particularly while descending the switchbacks above Ptarmigan Lake. From high above the water, hikers can appreciate the full scale of the glacial basin, with Crowfeet Mountain rising across the valley and the colorful cliffs of the Ptarmigan Wall surrounding the lake.

Once back at Ptarmigan Lake, the route retraces its path through the alpine meadows and forests to the Iceberg Lake junction before descending toward the Swiftcurrent Valley and the trailhead. Although most of the return trip is downhill, hikers should not underestimate the distance. At roughly 11 miles round trip, this is a substantial hike, especially when combined with the elevation gain and exposed terrain near the tunnel.

For hikers willing to tackle the mileage and elevation gain, the Ptarmigan Tunnel Trail is one of the most rewarding hikes in the Many Glacier area. Few trails in Glacier National Park offer such a dramatic progression of landscapes in a single day: dense forest, waterfalls, wildlife habitat, wildflower meadows, Ptarmigan Lake, colorful sedimentary cliffs, barren alpine slopes, enormous mountain peaks, and finally a historic tunnel blasted directly through a sheer mountain wall.

More importantly, Ptarmigan Tunnel isn't simply the destination—the transformation that occurs when hikers walk through it is what makes the hike unforgettable. One moment you're standing above the turquoise waters of Ptarmigan Lake surrounded by the mountains of Many Glacier; a few minutes later, you're staring into the vast Belly River wilderness with the mountains of northern Glacier National Park stretching toward Canada. For anyone searching for a challenging Many Glacier hike with incredible mountain scenery, fascinating history, and one of the most unique destinations in Glacier National Park, hiking the Ptarmigan Tunnel Trail is difficult to beat. Experienced hikers who can tackle an even longer day should consider combining Iceberg Lake with Ptarmigan Tunnel, making one of the most scenic long day hikes in the entire park.