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.

Mount Rainier is circled by the Wonderland Trail and is covered by glaciers and snowfields totaling about 35 square miles (91 km2).

[6] The name of the mountain itself in Lushootseed is "Tacoma", (pronounced "Taquoma") the same as a nearby city in the Puget Sound region.

[7][8] A more substantial archeological find was a rock shelter near Fryingpan Creek, east of Goat Island Mountain.

[7][8] In 1963 the National Park Service contracted Washington State University to study Native American use of the Mount Rainier area.

Smith also came to tentative conclusions that the park was divided among five tribes along watershed boundaries; the Nisqually, Puyallup, Muckleshoot, Yakama, and Taidnapam (Upper Cowlitz).

Subsequent studies cast doubt on Smith's theory that the tribes had agreed upon boundaries before they entered into treaties with the United States in 1854–55.

[11][12] The trip to Mount Rainier had played a role in reinvigorating Muir and convincing him to rededicate his life to the preservation of nature as national parks.

When the Pacific Forest Reserve was created in 1893, Muir quickly persuaded the newly formed Sierra Club to support a movement to protect Rainier as a national park.

Other groups soon joined, such as the National Geographic Society and scientific associations wanting Mount Rainier preserved as a place to study volcanism and glaciology.

Congress eventually agreed, but only after acquiring assurances that none of the new park was suitable for farming or mining and that no federal appropriations would be necessary for its management.

[9] Mount Rainier National Park closed because of extensive flooding as a result of the November 6, 2006 Pineapple Express rainstorm when 18 inches (460 mm) of rain fell in a 36-hour period.

[17] Beginning in 2024, timed entry reservations will be required for vehicles using entrances on the Paradise and Sunrise corridors during daylight hours in the peak summer months.

The system was implemented due to increased crowding at the park between July and September, when 70 percent of the annual 1.6 million patrons visit and cause traffic congestion.

[5] Mammals that inhabit this national park include cougar, black bear, raccoon, coyote, bobcat, snowshoe hare, weasel, mole, beaver, red fox, porcupine, skunk, marmot, deer, marten, shrew, pika, elk, and mountain goat.

The common birds of this park including raptors are the thrush, chickadee, kinglet, northern goshawk, willow flycatcher, spotted owl, steller's jay, Clark's nutcracker, bald eagle, ptarmigan, harlequin duck, grouse, peregrine falcon, Canada jay, golden eagle, grosbeak and finch.

Pink salmon spawn on odd-numbered years in heavy numbers up the White River near the park boundary.

According to the United States Department of Agriculture, the Plant Hardiness zone at Sunrise Visitor Center (6,398 feet (1,950 m) elevation) is 6a with an average annual extreme minimum temperature of -5.5 °F (-20.8 °C).

During the spring, the remaining snow and waterfalls are visible from many trails and other portions of the park; a summertime wildflower bloom in July and August also attracts many visitors.

Ohanapecosh /oʊˈhænəpɪkɔːʃ/ is a campground (with 188 individual sites and 2 group sites, open from late May through late September), visitor center (closed during the 2013 season), and ranger station located in the southeastern portion of the park, approximately 3 miles (4.8 km) from the park boundary off State Route 123.

Located in a deep valley among old growth forest at an elevation below 2,000 feet (610 m), it is the only developed area of the park without a view of Mount Rainier.

The Carbon River Entrance Station is located in the northwest corner of the park off State Route 165 and is the site of the only rainforest at Mount Rainier.

[52][53] A regional airport was proposed for several sites in southern Pierce County that would be 17 to 23 miles (27 to 37 km) from the park.