Bear Spray I don't live there and haven't ever been to Glacier, but I would guess it is like the rest of the worlds natural bear habitat, watch where you are stay away from them once spotted, never get between mamma and her cubs and all ways make sure you can out run at least one member of your group. If you are where you can carry a firearm make sure it is big enough to do the job.
Thousands of people go in and out of the wilderness WITHOUT guns and bear spray. The bears want as much to see you up close as you do them. You are more likely to have a visit in your camp because people are sloppy campers, and leave things out. A cooler is like asking them in for a snack. I put them in the truck bed put a dark colored tarp over it and shut the camper shell up.
On the East side there are two campgrounds St, Mary's and Rising Sun about half way between the two there is a huge open meadow on the North side of the road, early AM or just before the sun goes down there will be a Bear Jam (many cars stopped in the road) with cameras, spotting scopes, bino's out and looking at the Bears, Elk, Deer, Coyotes, happens everyday same time same place.
On the West side most the viewing takes place on the road the lines the border of the park from the West entrance to Polebridge, We like this better its got bigger bears, Elk, Deer, and the occasional wolf pack and the view of the river that runs parallel to the North Fork road its GREAT FISHING, and Really nice to look at. When we tent camped we use to take the kids there and jump in the river to get cleaned up. This spot is the only place in the park that I would say that you have to be VERY BEAR AWARE, especially if your fishing, they don't care who catches them, the fish are THEIRS!!