Mount Adams (Washington)

Mount Adams is an stratovolcano located in the Cascade Range of Washington, United States. Standing at 12,276 ft (3,742 m) feet, it is the second-highest mountain in Washington and a prominent feature within the Cascade Volcanic Arc, which formed as a result of the subduction of the Juan de Fuca Plate beneath the North American Plate. Adams is near two more-frequently erupting neighbors, Mount St Helens and Mount Rainier. It has twelve named glaciers descending its slopes.

Geologically, Mount Adams first formed in the Pleistocene. Its construction involved multiple eruptive phases, the first around 500,000 years ago, followed by the development of the modern cone around 10,000 years ago. The most significant recent activity was the Trout Lake Mudflow, approximately 6,000 years ago. The volcano has the potential for future hazards, including lahars, pyroclastic flows, and ashfall. Its deeply eroded flanks drain into major regional rivers like the Cispus, Klickitat and Lewis Rivers.

The mountain is home to diverse ecological zones, ranging from dense lower-elevation forests dominated by Douglas fir and western hemlock on its western slopes to drier ponderosa pine forests on its eastern slopes. These ecosystems support a rich array of flora and fauna, including large mammals like Roosevelt elk and black-tailed deer, as well as a variety of bird species and abundant wildflowers in the summer months.

The Yakama Nation, who reside on the eastern slopes, incorporated the mountain into their legends before the Europeans arrived. European-American explorers first documented the peak in the early to mid-19th century. The mountain was officially named after President John Adams in 1853, although the assignment of the name to the peak was due to mapmaker confusion. The first recorded ascent was made in 1854. Today, a significant portion of Adams is designated as the Mount Adams Wilderness.

Mount Adams is a popular destination for outdoor enthusiasts, offering a range of activities. Mountaineering is prominent, with the non-technical South Spur being the most common climbing route to the summit. Hiking, backpacking, and camping are popular throughout the warmer months. The Pacific Crest Trail traverses the western flank of the mountain. In winter, visitors enjoy cross-country skiing and snowshoeing.