I was in charge of the National Forest, which borders Glacier on the west side - the Flathead National Forest. I am very familiar with Glacier. It is difficult to find space, and often they are small and quite close. An alternative is to camp in National Forest campgrounds outside the park, and make day trips if you cannot find something inside the park. You can bushwhack up the North Fork of the Flathead River, and go in thru the Polebridge entry. There are also National Forest camp grounds. Across Highway 2 in Hungry Horse, is the Hungry Horse Reservoir.. Check out places there. For real adventure, Drive up the East side of the Reservior to Spotted Bear Campground. Very remote feeling, but you are long a few miles down from the ranger station. The South Fork of the Flathead River is knock-down-dead beautiful.
Go to youTube and search Flathead National Forest. There is a short video with amazing. landscape, an the fly over of the trail and river are in it. The scene of the fly fishing off the big rock in the river is just up from the Camp Ground. If you need to, you can call me for more details. I am a retired Forest Service Supervisor. We are considering a Oliver to take to Montana each summer.