Leashed dogs are allowed in developed areas: park roads and pullouts, frontcountry campgrounds, picnic areas, and parking lots, plus the paved Apgar-to-West Glacier bike path when it's free of snow. Not on any trail, lakeshore, or in the backcountry.
All trails, lakeshores outside developed areas, the backcountry, and buildings.
6 feet maximum, at all times.
Service animals are allowed where pets are not, under the ADA. A leash is still required.
The surrounding Flathead National Forest allows leashed dogs on most trails.