This acidic meltwater 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. 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.
Many routes exist up Mount Adams with the South Climb route the most popular.
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. This trail is very scenic with rolling grades around the base of Mt. Adams. The adjacent slopes are abundant with wildflowers and small subalpine fir.