Diamond Peak Wilderness preserves a large, mostly undeveloped stretch of Oregon’s central Cascade Range around Diamond Peak, an 8,744-foot shield volcano. First established in 1957 as the Diamond Peak Wild Area, it gained federal wilderness protection after the Wilderness Act of 1964 and was expanded in 1984 to 52,337 acres. Glaciation shaped its volcanic terrain, leaving snowfields, meadows, forests, and many small lakes. Spanning the Willamette and Deschutes national forests, the area supports varied wildlife adapted to wetter western and drier eastern slopes. It is also a major recreation destination, with trails including part of the Pacific Crest National Scenic Trail and routes used for climbing and winter travel.