Mount Rainier, highest mountain (14,410 feet [4,392 m]) in the state of Washington and in the Cascade Range. It lies 40 miles (64 km) southeast of the city of Tacoma. Covering 100 square miles (260 square km), the mountain is surrounded by the largest single-mountain glacier system in the United States outside Alaska, with 41 glaciers radiating from the broad summit. A dormant volcano, which last erupted 2,000 years ago, it lies within the Mount Rainier National Park (created 1899). The mountain contains three major peaks--Liberty Cap, Point Success, and Columbia Crest--and is noted for dense stands of coniferous trees on lower slopes, scenic alpine meadows, waterfalls and lakes, and an abundance of wildlife and flowers.