High Quality Content by WIKIPEDIA articles! The Glacier Peak Wilderness, created by the US Forest Service in 1960 by efforts of the North Cascades Conservation Council, four years before the 1964 wilderness legislation of the Congress, is located within portions of Chelan County, Snohomish County, and Skagit Counties in the North Cascades of Washington. The area, 572,000 acres (2,310 km2) in size, 35 miles (56 km) long and 20 miles (32 km) wide, lying within parts of Wenatchee National Forest and Mount Baker National Forest, is characterized by heavily forested stream courses, steep sided valleys, and dramatic glacier-crowned peaks.