Twanoh State Park Campground

Mount Rainier National Park ( ray-NEER) is a national park of the United States located in southeast Pierce County and northeast Lewis County in the U.S. state of Washington. The park was established on March 2, 1899, as the fourth national park in the United States, preserving 236,381 acres (369.3 sq mi; 956.6 km2) including all of Mount Rainier, a 14,410-foot (4,390 m) stratovolcano. The mountain rises abruptly from the surrounding land with elevations in the park ranging from 1,600 feet to over 14,000 feet (490–4,300 m). The highest point in the Cascade Range, Mount Rainier is surrounded by valleys, waterfalls, subalpine meadows, and 91,000 acres (142.2 sq mi; 368.3 km2) of old-growth forest. More than 25 glaciers descend the flanks of the volcano, which is often shrouded in clouds that dump enormous amounts of rain and snow.

The park has several entrances that lead to three general areas: Paradise, the Carbon River and Mowich Lake area, and Sunrise. It had over 1.6 million visitors in 2024. Mount Rainier is circled by the Wonderland Trail and is covered by glaciers and snowfields totaling about 35 square miles (91 km2). Carbon Glacier is the largest glacier by volume in the contiguous United States, while Emmons Glacier is the largest glacier by area. Mount Rainier is a popular peak for mountaineering with some 10,000 attempts per year with approximately 50% making it to the summit.