Fish Creek is one of the few campgrounds at Glacier National Park that accepts reservations. It also happens to be a very nice campground, so for people who can plan their trip several months in advance, reserving at Fish Creek is a great way to go.
The campground is laid out on four loop roads set in deep forest more like the Pacific Northwest than Montana. The sites are generally very widely separated from each other, so this campground feels very private and is also very quiet. Flush toilets, showers in Loop A, and plenty of water spigots make this a well-equipped national park campground. Loop C is closest to the lake with a row of sites along the shore, though the thick trees prevent much of a view. Maybe even better, one side of Loop B sits above Fish Creek, and the sound of the creek is very pleasant.
Fish Creek is a great base for exploring the west side of Glacier. Excellent hikes like Avalanche Lake, John’s Lake, and Trout Lake are nearby. At Apgar Village, there are rental boats and bikes, plus a large beach (but the little beach near C Loop is just as nice and much more private).