The first 2.7 miles is on the shared Iceberg-Ptarmigan Trail, a well-defined, gently-graded approach. This trail is commonly frequented by Glacier's grizzly bears, so check with the rangers before setting out. At 2.7 miles, the shared trail splits, take the right option to Ptarmigan Lake.

Starting this hike early makes it possible to avoid many of the hikers heading up the Iceberg-Ptarmigan Trail and even more likely to enjoy solitude once on the Ptarmigan Trail. This is a popular route, but the vast majority of hikers tend to start mid-morning.

There are some beautiful views where the Iceberg-Ptarmigan Trail is out in the open. Then, it snakes up through a lovely wooded stretch before passing by Ptarmigan Falls on a nice footbridge. This makes a wonderful place to take a breather before continuing on.

Not long after the falls is the well-signed intersection with the Iceberg Lake Trail. From the intersection, the trail climbs a bit more seriously as it passes through woods, then leaves the trees behind. After crossing some large meadows, and traversing a scree field, the sparkling little Ptarmigan Lake appears. Enjoy the serene setting before embarking on the final ½ mile.

Until this point, the elevation gain is fairly mild, but the switchbacks leading to the tunnel way up near the top of the wall steepen considerably. Thankfully, these switchbacks ascended in a relatively friendly manner, making the ascent simply a matter of putting one-foot-in-front-of-the-other.

Within a ½ mile, the goal of the hike opens up at the mouth of the tunnel! The tunnel was built back in 1931 by the CCC (Civilian Conservation Corp). The men had to blast through the Ptarmigan Wall to create the 240' long tunnel, which connects the Belly River Valley at the north end with the Many Glacier Valley at the south end. Walk through the tunnel for a breathtaking view of Elizabeth Lake sitting pretty down in the Belly River Valley. While savoring the views, reflect on the sheer amount of work and the magnificent force it required of the CCC to build so many National Park trails.

Once sated, hike back through the tunnel, then descend past Ptarmigan Lake and on to the trailhead to complete this memorable 10.5-mile trek.