20 Iceberg Lake

Type of hike: Out-and-back

Total distance: 9.0 miles (14.6 km) round-trip

Time required: 5 to 8 hours

Elevation change: 1,194-foot gain

Finding the trailhead: The trail departs from the Iceberg-Ptarmigan Trailhead, at the north end of the Swiftcurrent Motor Inn complex, among the cabins behind the coffee shop. A parking pullout there is marked with a trailhead sign.

The Hike

Iceberg Lake is a striking aquamarine tarn surrounded on three sides by towering cliffs. Ice-out may not occur here until mid-July, and the bergs for which the lake was named may be seen floating about well after that date. This stunning destination plus the brilliant wildflowers along the route make the Iceberg Lake Trail one of the most popular hikes in the park. It crosses fine grizzly bear habitat, and bears are frequently seen on the open slopes on both sides of the trail.

The hike begins as a short connecting trail that climbs briskly for several hundred yards to join the main trail coming in from the hotel. The trail then turns northwest, climbing gently along the open slopes high above Wilbur Creek. Look for the magenta spikes of fireweed and the bulblike inflorescences of beargrass (a member of the lily family) early in the season. The trail passes below Altyn Peak, a greenish massif of Appekuny argillite. Mount Wilbur, known to the Blackfeet people as “Heavy Shield Mountain,” rises across the valley to the south. The trail passes into open forests on its way to Ptarmigan Falls, a popular rest stop on hot summer days.

Shortly after passing the falls, the trail reaches the junction with the Ptarmigan Tunnel Trail, then turns southwest along the Ptarmigan Wall through increasingly alpine scenery toward the head of the valley. Looking south, hikers can glimpse a waterfall on Iceberg Creek through the trees. The trail climbs gently as it curls south into the glacial cirque that holds Iceberg Lake.

The 3,000-foot cliffs surrounding the lake provide prime escape habitat for mountain goats, which frequent this area. Talus slopes along the lake’s south shore are home to a variety of small mammals, including pikas and ground squirrels. The permanent snowfields at the head of the lake are remnants of a glacier that until recently occupied this basin beneath the cool shadows of Iceberg Peak.

Key Points

0.0 Start at trail sign.

0.1 Junction with Trail 167. Turn left for Iceberg Lake.

2.3 Trail crosses Ptarmigan Creek at Ptarmigan Falls.

2.4 Junction with Ptarmigan Tunnel Trail. Stay left for Iceberg Lake.

4.4 Trail crosses Iceberg Creek below a nameless tarn.

4.5 Iceberg Lake. Return the way you came.

9.0 Arrive back at trailhead.