Added 2021-09-16
Piegan Pass Trail is an intense climb in Glacier National Park. It's a long point-to-point trail, so it requires planning on how to get back to your car. The park has a shuttle service that should take you from Many Glacier to St. Mary. For more information on the shuttle, see here.
If you're not an expert hiker, you might enjoy this trail more as an out and back adventure instead. The first three miles up are the easiest. This trek through the wooded area would make for an enjoyable stand-alone hike.
If you do summit the pass, there are fantastic views of Jackson Glacier and the surrounding canyons. The way back down will be steep and rocky. The trail is a great way to experience the forest, a ridgeline, and alpine meadows.
Depending on the time of year, you might run into snow and slippery rocks as you climb higher.