scenic area of the Cascade Range in west-central Washington, U.S., about 35 miles (56 km) southeast of Tacoma and some 30 miles (48 km) northeast of Mount St. Helens National Volcanic Monument (Saint Helens, Mount). The park was created in 1899 to preserve Mount Rainier (Rainier, Mount), a dormant volcano 14,410 feet (4,392 metres) high, and the surrounding area. It covers 368 square miles (953 square km).

The peak was sculpted by ice, and 41 glaciers remain around the summit area. The park receives large quantities of precipitation annually, especially on the western slope of Mount Rainier. Coniferous trees predominate, and the lower elevations have dense forests of giant Douglas firs, western red cedars (giant arborvitae), and mountain hemlocks. During the warm months, the subalpine and alpine meadows are covered with wildflowers that bloom progressively higher up the slopes as the summer passes. The park's wildlife is abundant and varied. Black-tailed deer, Roosevelt elk, bears, and mountain goats are the largest animals; there are also raccoons, squirrels, and other small mammals. More than 140 species of birds (many of them migrants) can be found there, including the Steller's jay, Clark's nutcracker, and white-tailed ptarmigan.

The park, with its easy access from the nearby Puget Sound urban area, is a popular destination for visitors. It is one of the country's premier hiking and mountain climbing areas. The Pacific Crest National Scenic Trail skirts portions of the park's eastern boundary.