No you can’t trust it at all.
You could have an 8-foot electrified fence and I still wouldn’t sleep peacefully in grizzly country, not with food in the tent.
You should see the electrified mini-fortresses beekeepers put up to protect their hives...drive by them one day, as tight and secure and orderly as an accountant’s office.
Next week it’s all a shambles, like a tornado hit it.
I posted the bit about the tiny little fence just to show how greatly the visitors underestimated the power of a grizzly. They will tear off the door of a parked, locked vehicle if there is something in there they smell and want.
Doesn’t take them much effort either...stick their giant claws in around the door seal and boom! They are eating your frito-lays.
Going through Yellowstone, saw a guy who had just hiked out holding on to what was left of his face after a grizzly attacked him.
Apparently he was photographing bears and was surprised by one.