Near Big Spring State Park in central Pennsylvania lies the Hemlocks Natural Area. Made up of about 120-acres of rare old-growth forest, the region became a National Natural Landmark in 1972. There, Hemlock trees over 100 feet tall and hundreds of years old grow amidst tulip poplar, black gum, oak, and basswood trees.
A small stream called Patterson Run runs through the area, with ascending slopes on either side — this terrain may explain why the environment was spared the clearcutting that most Pennsylvania forests experienced.
Source(s): @endlessmountains.wordpress.com/2015/10/22/hemlocks-natural-area/.
