Glacier Peak is a volcanic cone of basalt, pumice, and ash which erupted during periods of heavy glaciation.

Various species of wildlife inhabit the area and include deer, elk, black bear, mountain goat, cougar, marten, and lynx.

[2] The last confirmed grizzly bear sighting in the United States portion of the North Cascade ecosystem occurred in this wilderness.

[2] No roads approach Glacier Peak, and many miles of hiking through extremely rough terrain are required to reach its base.

[2] This article incorporates public domain material from websites or documents of the U.S. Forest Service.