The park contains numerous mountains, waterfalls, large and small lakes and a few small and rapidly melting glaciers. Triple Divide Peak is a mountain on the divide between the Pacific Ocean, Hudson Bay and Gulf of Mexico watersheds. Lake McDonald, Two Medicine Lake, St. Mary Lake and Lake Sherburne are large lakes while small tarns are located in cirques throughout the mountains. The north fork of the Flathead River forms the western boundary of the park.
There are about 50 small glaciers in the park. They range in size from the 1.74 kmē Blackfoot Glacier to the 0.06 kmē Gem Glacier. In total 27 kmē of glaciers exist in the park in 2003. Other well-known glaciers include Grinnell Glacier, the Salamander and Jackson Glacier. There were 150 glaciers in the area of the future park in 1850. The larger glaciers are only 1/3 of their 1850 size and it is estimated that all the park's glaciers will have melted by 2030.
The Great Northern Railway completed a railroad through the area south of the park in 1891. In 1900 the park was designated a forest preserve; although, mining was still allowed, it was not commercially successful. In the 1910s, to promote tourism the railway built a series of hotels and backcountry houses on a Swiss chalet theme throughout the area. Vacationers could take horse trails between lodgings. Many of these are still in use today. The Great Northern Railway in developing its "American Alps" was following the example of the Northern Pacific Railroad in Yellowstone and the Atchison, Topeka, and Santa Fe Railroad at Grand Canyon.
Several large lakes have small wooden tour boats, some dating back to the 1920s. Going-to-the-Sun Road, completed in 1932, is the only road that crosses the park, going over the Continental Divide at Logan Pass. A fleet of 1930s red tour buses, rebuilt in 2001 to run on propane, offer tours on the road.
Glacier is part of a large preserved ecosystem. Glacier Park borders the Blackfeet Indian Reservation, Flathead National Forest, Great Bear Wilderness, Lewis and Clark National Forest in the United States and Waterton Lakes National Park, Akamina-Kishinena Provincial Park and the Flathead Provincial Forest in Canada.
Wildfires in 2003 on the west side of the continental divide burned 10% of the park. There were also extensive fires in the surrounding forests.
There is also a national park in Canada by the same name.