Boyd Big Tree Preserve Conservation Area is a largely undeveloped Pennsylvania state park on Blue Mountain in Dauphin County, managed to protect mature woodland rather than provide extensive recreation facilities. Donated to the state by Alex Boyd in 1999, it serves as a sanctuary for old trees, wildlife habitat, and environmental education, with no through roads or camping and only limited improvements. Its forests support deer, black bear, turkeys, grouse, squirrels, bluebirds, warblers, and migrating hawks. Recreation focuses on low-impact use, including trails for hiking and cross-country skiing, while hunting is permitted on much of the property under state game regulations.