Wonder Mountain Wilderness is a protected area in Olympic National Forest on Washington’s Olympic Peninsula, covering 2,349 acres around Wonder Mountain beside Olympic National Park and managed by the U.S. Forest Service. Its roughly triangular terrain rises along a high southern ridge to the 4,848-foot summit, with dense forests of western hemlock, Douglas fir, and silver fir below. Along McKay Creek and Five Stream, vegetation includes alder, willow, vine maple, huckleberry, and thimbleberry. Congress established it in 1984 as one of five wilderness areas in the forest. With no trails and seasonal road closures, the area remains especially isolated.