Along the west slope of Mt. Adams lies the 47,280-acre Mt. Adams Wilderness. The 12,326-foot high Mt. Adams is the second highest peak in the Northwest after Mt. Rainier. Mt. Adams Wilderness is bounded on the east by the Yakama Indian Reservation. Wilderness trails offer the hiker spectacular views of Mt. Adams and its glaciers, tumbling streams, open alpine forests and wildflowers scattered among lava flows and rim rocks. Since the eruption of Mount St. Helens, Mt. Adams has become a popular attraction for mountain climbers.

Here you'll find a unique blend of dry east side and moist west side weather conditions which allow diverse types of vegetation to flourish. The area has a complex geologic history that continues even today.

You can find active glaciers methodically carving away the mountain, and the dramatic trace of avalanches that substantially altered the landscape. Even the volcanic activity in the area is fairly recent: some occurred a mere 3,500 years ago-bare moments on the scale of geologic time.

Taken all together, these qualities provide the visitor opportunities for a rich and varied experience. We hope you enjoy your visit. Thanks for your help in preserving the unique character of the Mount Adams Wilderness.

Many routes exist up Mount Adams with the South Climb route the most popular. While these routes provide a wide range of difficulty, all mountain climbing, whether a "walk up" or "technical climb", is a potentially dangerous activity.

All climbers need to be prepared to deal with a wide variety of weather, snow, and rock conditions. Detailed information on climbing routes is available from a number of climbing guidebooks. Consult these as you plan your trips. In addition to the ten essentials for outdoor recreation (map and compass, whistle, flashlight, extra food and water, warm clothing, a first-aid kit, sun glasses and sun screen, waterproof matches, a candle or fire starter, and a pocket knife), equipment should include sturdy hiking boots, ice ax, crampons, and ropes when travelling on glaciers. For more information, see  Mt. Adams Climbing Permit Applicaion.

The mountain as we see it today is the result of volcanic activity and the effects of glaciers on those volcanic deposits. The events listed below are among the most dramatic (but certainly not the only!) events responsible for the shape of Mount Adams as we know it today.

Among all the volcanic peaks in the Pacific Northwest, Mount Adams has a rich and varied history. Adams lacks the symmetry which often characterizes volcanic cones. Instead, it is a long ridge composed of a complex of several cones that grew from volcanic flows occurring over successive ages.

• 450,000 years ago; oldest eruptions associated with mount Adams.
• 25,000 to 12,000 years ago; the period of most recent cone-building. The entire mountain above timberline was constructed in a series of eruptions issuing at the true summit, south summit, and Suksdorf Ridge.
• 21,000 to 12,000 years ago: the last major glacial expansion when ice covered virtually the entire Wilderness. Tongues of glacial ice extended well down many of the surrounding valleys. The glaciers smoothed and streamlined formerly rough lava surfaces. These surfaces are now covered by deep glacial deposits or more recent lava flows. The road to Morrison Creek and Cold Springs ascends one of these glacier-formed ridges (also called moraines).
• 5,100 years ago: the Pinnacle was formed by a great avalanche. Sulfur gasses (mostly hydrogen sulfide) combining with melt water from the ice cap created sulfuric acid. This acidic melt water flowing from the summit, severely weakened the summit rocks resulting in a dramatic avalanche. Debris from this avalanche flowed down the White Salmon River to the Trout Lake Valley. The many large yellow-brown rubble boulders around the valley are conspicuous reminders of this great avalanche.
• 3,500 to 6,000 years ago: the Muddy Fork and Aiken Lava Flows moved down the flanks of Mount Adams, the latest-but probably not the last-volcanic activity of Mount Adams.
• Twentieth century: in 1983 and 1921 large avalanches broke off the Avalanche and White Salmon Headwall-the same headwall created by the great avalanche 5,100 years ago.
• The 1921 avalanche fell nearly one mile, covering almost 6,000 acres with debris. Other avalanche deposits are prominent at Devils Garden, Avalanche Valley, and along the Big Muddy below the Klickitat Glacier.