The Maryland Conservation Corps (MCC) partners with the Maryland Forest Service (MFS) and the Maryland Department of Agriculture’s (MDA) Forest Pest Management team each fall and spring to protect the state’s eastern hemlock forests from the hemlock woolly adelgid (HWA).
On a cold and rainy week in May, 45 MCC and Veterans Conservation Corps members, park staff, Watershed and Climate Services staff, and forestry staff treated 3,825 trees in Savage River State Forest’s Wolf Swamp area, providing the trees with seven years of protection from this invasive pest.
This joint project started over a decade ago, and the collaboration has resulted in the treatment of over 82,638 trees in the past 16 years, serving as a vital tool for forest conservation while training hundreds of young people in hands-on conservation.
Eastern hemlocks are vital to Maryland’s biodiversity, hosting 120 wildlife species and regulating stream health. They buffer pollution and sediment, and provide critical shade to regulate water temperature in creeks.
Without intervention, a hemlock woolly adelgid infestation can drain a tree’s energy reserves and kill it in just four years. Some of Maryland’s forests have suffered, such as Cunningham Falls State Park, where HWA killed nearly every tree in a falls-adjacent stand of eastern hemlocks within three years in the late 1990s.
Treating hemlock woolly adelgid tree by tree is labor-intensive. It involves measuring each tree, injecting soil-based or stem-injected pesticides, and tagging specimens.
Ultimately, this project continues the legacy of the Civilian Conservation Corps (CCC). By maintaining the health of old-growth forests, MCC members ensure that Maryland’s natural beauty remains unchanged for future generations. While biocontrol research offers hope for a permanent solution, MCC remains on the front line, buying time through diligent service. Their work prioritizes ecological need over prestige, ensuring that Maryland’s most diverse ecosystems do not collapse.
ALT Spring 2026 hemlock woody adelgid team - Maryland Conservation Corps members and crew leaders, Park Service staff, DNR Forestry and Watershed and Climate Services staff, and Maryland Department of Agriculture Forest Health team members.
ALT MCC Crew member Hannah Moore carefully measures pesticide with Forestry’s Alanna Crowley, under the supervision of MDA’s Patrick Simons and Daniel Lewis.