Mohawk Trail State Forest is specifically known for its tall trees. A total of of the state forest is classified as pre-settlement old growth by researchers. Trees approaching 500 years in age have been confirmed. Most of the extremely old trees are Eastern hemlock. Other species reaching significant age include yellow and black birch, sugar maple, red spruce, and northern red oak. Specimens of examples of all these species exceed 300 years in age and numerous trees of a dozen species surpass 200 years. Trees over 150 years old in Mohawk are very common.