Mount Rainier (Mt. Rainier), also known as Tahoma or Tacoma, is a huge active stratovolcano in Mount Rainier National Park in the Cascade mountain range of the United States, located 59 miles southeast of Seattle.
The mountain is geologically young, having been produced by a series of lava flows from eruptions that began around a million years ago. The last time the dormant volcano erupted was roughly 150 years ago. Rainier is surrounded by the biggest single-mountain glacier system in the United States outside of Alaska, covering 100 square miles (260 square kilometers).
Nisqually Glacier, whose retreat and advance over the last 150 years has helped scientists establish patterns in the Earth’s climate, is one of two dozen recognized glaciers and a number of smaller patches of permanent ice and snow radiating from the vast top. Liberty Cap, Point Success, and Columbia Crest are the three prominent peaks on the mountain (the latter is the summit, located on the rim of the caldera).
On its lower slopes, Rainier is known for dense stands of coniferous trees, picturesque subalpine and alpine meadows—with a profusion of wildflowers during the summer months—waterfalls and lakes, and a plethora of wildlife.