3. Acadia National Park (Maine)
The first national park on the East Coast, Acadia National Park is home to the tallest mountain on the U.S. Atlantic coast. The rugged coast of Maine is home to beautiful granite peaks, historic carriage roads and large woodland areas. One of the most dog-friendly of all national parks, pups are permitted on 100 miles of hiking trails and 45 miles of carriage roads throughout the park! They must be leashed at all times and are NOT allowed on Sand Beach, Echo Lake Beach, Isle au Haut campground, ladder trails, public buildings, and lakes that are public drinking water supplies.