Ptarmigan Trail

Overview

This is Many Glacier at its boldest: a 10.6‑mile total, out‑and‑back trek with about 2,300 feet of gain to a 250‑foot tunnel blasted through the Ptarmigan Wall. Expect 7–8 hours for most hikers with breaks. The route strings together shady forest, a thundering waterfall, a turquoise alpine lake, and a dramatic, exposed finale to the tunnel—then flips the scenery to the remote Belly River country on the far side. It’s strenuous and exposed up high, but absolutely worth the effort when conditions and the tunnel doors are open.

Route breakdown

Start at the Iceberg–Ptarmigan Trailhead behind Swiftcurrent Motor Inn. A short, steep connector puts you on the main trail shared with Iceberg Lake for the first ~2.5 miles to Ptarmigan Falls—there’s a pit toilet just before the overlook and reliable flowing water to filter. Cross the footbridge and take the signed right toward Ptarmigan Tunnel. The grade steepens through berry patches, then eases as you reach Ptarmigan Lake around 4.3–4.5 miles—an ideal refuel stop. From the lake, traverse red argillite talus to two steep, windy switchbacks that gain roughly 500 feet in under a mile to the tunnel. South‑side views sweep over Ptarmigan Lake and Many Glacier. Walk through the dark tunnel and you’re suddenly above Elizabeth Lake and the Belly River drainage; continue a short way along the hewn ledge for the best panoramas before turning around.

Geology and wildlife

You’ll see a striking dark band slashing across Ptarmigan Wall and Mount Wilbur: a diorite sill that intruded into ancient Siyeh Limestone, baking some into marble. The tunnel bores through vivid red argillite interlayered with quartzite—hard, beautiful walking country. Wildlife is a real possibility here: grizzly bears commonly forage along the lower miles (especially in berry zones), and mountain goats and bighorn sheep often patrol the lake basin and upper slopes. Make noise, hike in a group if you can, and carry bear spray where you can reach it.

Logistics

Parking is limited at the small lot behind Swiftcurrent Motor Inn; overflow at the Motor Inn adds a short walk. Restrooms are at the Motor Inn, with a pit toilet near Ptarmigan Falls. Top off water at the Motor Inn and plan to filter en route at Ptarmigan Creek if needed. If you’re short on time or if conditions deteriorate, Ptarmigan Lake makes a satisfying turnaround—save the tunnel for a better day.

Best time to hike

The tunnel doors typically open mid‑July to late September, and snow can linger on the upper switchbacks into summer. Mornings bring calmer winds, clearer views, easier parking, and nicer light on the lake and wall—start early. Many Glacier trails occasionally close for bear activity; check current trail status the morning of your hike. On hot or windy afternoons, that final exposed mile can feel endless.

Safety and tips

The last mile is steep and exposed, with loose gravel underfoot and frequent strong winds—trekking poles and grippy footwear matter. A small headlamp makes the short tunnel passage more comfortable. If the doors are closed, do not attempt to bypass them. Past the tunnel, the north‑side ledge has airy drop‑offs—watch footing, especially with ice, lingering snow, or gusts.