Susan K. Hagle, USDA Forest Service, Bugwood.org

USDA Forest Service - Northern and Intermountain Region , USDA Forest Service, Bugwood.org

Minnesota Department of Natural Resources - FIA , Minnesota Department of Natural Resources, Bugwood.org

USDA Forest Service , Bugwood.org

USDA Forest Service - Northern and Intermountain Region , USDA Forest Service, Bugwood.org

David J. Moorhead, University of Georgia, Bugwood.org