Hemlock State Forest Park
🏆🏆🏆🏆 Ancient Hemlock Forest — Small state forest park protecting a stand of old-growth eastern hemlock — one of the most threatened tree species in eastern North America
Hemlock State Forest Park protects a stand of old-growth eastern hemlock — a species facing catastrophic decline from the hemlock woolly adelgid, an invasive insect from East Asia. The adelgid has killed millions of hemlocks across the eastern US since its introduction in the 1950s — some estimates suggest 80% of eastern hemlocks could be lost within decades. Hemlocks are “foundation species” — their dense shade creates cool, moist microclimates along streams that are critical habitat for native brook trout (Pennsylvania’s state fish). Losing hemlocks means losing brook trout habitat.
Visitor Information
| Detail | Information |
|---|---|
| Location | Central PA |
| Entry Fee | Free |
| Crisis | 80% of hemlocks could die! |
| Impact | Brook trout habitat vanishing! |
About Hemlock
Hemlock State Forest Park in Columbia County preserves a stand of eastern hemlock — Pennsylvania’s state tree — in the Endless Mountains of northeastern Pennsylvania. Eastern hemlocks, which can live 800+ years, are under existential threat from the hemlock woolly adelgid, an invasive Asian insect that has killed millions of hemlocks across the Appalachians since the 1990s. Parks like this preserve increasingly rare old hemlock stands.
Things to Do
Hiking through the hemlock forest (observe these ancient trees while they survive), picnicking, fishing in mountain streams, hunting (seasonal), and witnessing the ecological crisis threatening Pennsylvania’s state tree.
Insider Tips
Hemlock groves: This park preserves stands of eastern hemlock — a species under severe threat from the hemlock woolly adelgid. Pro tip: Pennsylvania’s hemlock forests are declining rapidly — the woolly adelgid has killed millions of hemlocks. Stream ecology: Hemlocks shade cold-water streams that support native brook trout — losing hemlocks means losing trout habitat.
Best Time to Visit
Year-round: Evergreen hemlocks are green in all seasons. Summer: Cool shade under hemlock canopy. Spring: Stream fishing for brook trout. Winter: Snow on evergreen branches.
Frequently Asked Questions
What happens when hemlocks die?
When hemlocks die, stream temperatures rise (no shade), brook trout populations crash (too warm), and the forest understory changes dramatically. Hemlocks create a unique micro-climate — cool, moist, and acidic — that supports specialized plant and animal communities. Their loss transforms the ecosystem. Pennsylvania is treating high-value hemlocks with insecticide, but the scale of the crisis is overwhelming.
