Aeromagnetic map of the Glacier Peak Wilderness and adjacent areas, Chelan, Skagit, and Snohomish counties, Washington

The Glacier Peak Wilderness encompasses 464,741 acres, including 483 acres of patented mining and millsite claims. Also included in the present study are nine areas adjoining the wilderness (see fig. 1), totaling 90,034 acres of recommended wilderness additions. All these lands are here collectively called the “study area.” Access to the study area is provided by generally well maintained trails from gravel or dirt roads along major valleys above Darrington, Marblemount, Stehekin, Holden, Trinity, and Lake Wnatchee. Other than the main access trails across a few passes (Cloudy Pass, Buck Creek Pass, White Pass, and Indian Pass), trails are rough, infrequently maintained, or nonexistent.