Geologists consider this mountain to be an 'episodically active' volcano, meaning one that will erupt again some time in the future even though it may be quiet now. Mount Rainier is the tallest volcano and fifth highest peak in the contiguous United States. 5. I want to donate an artifact or photograph to the park. Whom should I contact? 5. Is it safe to visit Mount Rainier? New research indicates Mount Rainier is far more active than previously believed. We now understand there are risks associated with the volcano and its glaciers that require visitors and staff to be aware and prepared. Mud flows (also known as lahars) and glacial outburst floods can occur without warning, and could damage roads, invade campgrounds, and cause enormous injury to park visitors and staff. The Longmire Historic District, Cougar Rock, Ohanapecosh, Sunshine Point, Ipsut Creek and White River campgrounds are all vulnerable to geologic hazards. While many people believe the danger to be minimal, only you can decide if you want to spend time in this unpredictable and changing landscape. If you choose to visit, be sure to review information posted at park campgrounds and inns.