I went to Glacier National Park in the latter half of September with 3 other members of my backpacking club (Northeast Ohio Backpacking Club), all of whom had been to Glacier at least once before. Our plan was to acclimate with a couple of day hikes, then do two 5-day, 4-night backpacking trips, separated by a night at Many Glacier lodge for recuperation and resupply.
We had decided to drive (rather than fly) from Ohio, going straight through without stopping overnight. We left at 6 PM on September 13 and arrived in West Glacier at about 8 PM the next day, a 28-hour marathon. Our plan had been to camp for 3 nights at Apgar, one of the few campgrounds still open. However, Apgar was full, so we ended up in the Glacier Highlands motel in West Glacier for our first 3 nights. I highly recommend their restaurant if you are ever in the neighborhood (try the Razzleberry pie a la mode for a real treat).
On Sunday the 15th, the day looked beautiful and we decided for our first day hike to take the Highline trail from Logan Pass to the Garden Wall. We looked too quickly at the map and estimated this to be about 10 miles roundtrip. With our side hike up a spur trail to the top of the Wall, overlooking Grinell glacier, it ended up being more than 15 miles. So a bit more than we had bargained for. Nevertheless, the views were fantastic and the weather ideal and even a bit warm.