Pop-ups and bears
I was surprised to see this notice posted at Glacier National Park last week: I guess there occasionally is a concern.
Forum Discussion
I agree that bears can open the tin cans (campers)easily. I'm guessing the reason for not exposing the canvas sides is that smells/scents of food will pass through the canvas easier than through the aluminum or fiberglass sides. Thereby attracting the bears to check out what's inside.
