Have just been away last 4 days in Glacier. The highline trail is amazing. It starts off a little scary with sharp cliffs on one side, while you are walking along a rock wall holding on to a cable. But the views are breath-taking. We did it on the 17/07/10 and did half of it as a ranger-led hike, upto Haystack Butte. Lots of interesting information. The trail is definitely safe to complete now. We went through independently as the rangers were only doing the first 1/3rd of it, because of a couple of treacherous snowbridges. There are a LOT of people there already, so if you want peace and quiet, this is not the place. We saw many mountain goats, deer and marmots.
We got to the parking lot at Logan's Pass around 830 and half the car park was full. So if you plan to drive, get there early.
The trail starts above treeline and descends from there slowly. After Granite Chalet, the rest of the Loop trail is through the forest and sharply downhill (not easy on the knees). Lots of wildflowers along the way. Beautiful scenery and definitely recommended.
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