At 235,625 acres, the park includes old growth forests , subalpine terrain, more glaciers than any other mountain in the continental US, and is voted the volcano most likely to next erupt within the lower-48. Standing at 14,410 feet, Mt. Rainier approached by over 10,000 hopeful climbers each year, about half of whom make it to the top. Buried in snow and ice, the chances for a lahar from this volcano are very real and it stands as both beauty and threat to the south Puget Sound area. Millions live in its shadow and here, in the Northwest, it is usually referred to as the Mountain . Research conducted over the past few years indicates that Mount Rainier is a lot hotter than geologists believed.
Glacial floods are also a danger and avalanches happen regularly and do claim lives on the mountain.
The most recent lahar of significance happened about 500 years ago. The west flank of Rainier collapsed and the resulting mudflow covered the Puyallup valley, including the destruction of an an old-growth forest. The mud flows were large and long enough to reach Puget Sound. Mount Rainier is a young volcano, only about 1,000,000 years in comparison to the 12 million of the surrounding Cascade range. One in a long string of volcanoes along the Cascade Range, it is also considered the most perilous at this point in time, even overshadowing Mount St. Helens in what destruction could potentially occur from a major lahar or eruption.