Mount Rainier National Park236,381 acres around a 14,410-foot active stratovolcano — the fourth U.S. national park, established 1899, with 25 named glaciers and the 93-mile Wonderland Trail

Mount Rainier National Park was established March 2, 1899 as the country's fourth national park — the result of a multi-year campaign by the Mazamas mountaineering club, the Sierra Club, and Northern Pacific Railroad executive Bailey Willis to protect the 14,410-foot active stratovolcano dominating the Puget Sound skyline. The park's 236,381 acres span the Cascade crest from 1,600 feet at the Carbon River entrance to 14,410 feet at Columbia Crest. Ninety-seven percent is designated wilderness under the 1988 Mount Rainier Wilderness Act, and the entire park was named a National Historic Landmark in 1997 for its 1920s–30s NPS rustic-style architecture (Paradise Inn, Longmire's National Park Inn, the Sunrise day lodge).

The mountain is one of 16 Decade Volcanoes — the most dangerous in the U.S. by population at risk because of its lahar potential into the Puyallup and Nisqually river valleys. Its 25 named glaciers cover roughly 35 square miles; Carbon Glacier descends to 3,500 feet (the lowest glacier terminus in the contiguous U.S.) and Emmons Glacier covers 4.3 square miles on the northeast face. Paradise, on the south flank at 5,400 feet, is the most-visited spot in the park — wildflowers (lupine, paintbrush, avalanche lily) peak from mid-July through mid-August, and the Skyline Trail's 5.5-mile loop crosses Edith Creek, climbs to Panorama Point at 6,800 feet, and returns past Myrtle Falls. Sunrise on the northeast side, at 6,400 feet, is the highest point reachable by car in the park and the launch for Burroughs Mountain Trail's three summits.

Plan three to five days to do the park properly. The Paradise corridor (Nisqually Entrance → Longmire → Paradise) is the standard one-day visit; allow a separate full day for Sunrise (Highway 410 from Enumclaw, only open July–September), and another for the Carbon River / Mowich Lake roads on the wetter northwest side. Stay in Ashford (Nisqually gateway), Packwood (south side, gateway to Stevens Canyon), or Greenwater (north side, near Sunrise). Timed-entry reservations are required for Paradise and Sunrise corridors May through Labor Day weekend on Fridays through Sundays — reserve at recreation.gov 30 days out or arrive before 7 AM. Bring a rain shell year-round; Paradise averages 53 feet of snow annually and the upper meadows can be socked in even in August.