They are allowed in the campground and on a bike path to Apgar Village and in Apgar Village. The camp hosts are happy to point out the areas they are allowed.

Yes, must be on leash at all times. They are allowed to walked on the roadways and on the bike trails in West Glacier as long as leashed and you pickup their poop. Not allowed on the hiking trails or beach. Would recommend always carrying Bear spray when out walking too. Personally would not leave them outside on leash unsupervised either. Never know when a Bear will wonder through camp. Had one neighbor leave his camp stove out on the table and the rangers came by and put it in the bear storage unit, because he was not outside with the stove.

Yes. We had our two dogs with us when we stayed.