In contrast to Canada, National Parks in the United States are typically not dog friendly and Glacier National Park is no exception. That being said, depending on the type of traveler you are, bringing your dog on your Northwest Montana vacation may work out just fine.
In Glacier National Park
Dogs are not allowed on backcountry trails in Glacier National Park, which can be a big deal, since backcountry hiking is one of the most popular activities in the area. You CAN bring your dog into the park, and dogs on leash are allowed on roads, in the campgrounds, and in parking areas. Dogs on leash are also allowed in the village areas (Many Glacier, Lake McDonald, and Apgar). Dogs are also allowed on the bike trails around Apgar and along Highway 2 west of West Glacier.
Below: Chris and the dogs at the foot of Lake McDonald in Apgar Village.