The Grand Canyon of Pennsylvania is known for its fall foliage, and Colton Point State Park is a popular place to observe the colors, with the first three weeks of October as the best time to see the leaves in their full color. Red leaves are found on red maple, black cherry, and red oak, while orange and yellow leaves are on black walnut, sugar maple, tulip poplar, chestnut oak, aspen and birch, and brown leaves are from beech, white oak, and eastern black oak trees. Despite the logging, there are some old-growth hardwoods and hemlocks on Fourmile Run. Plants of "special concern" in Pennsylvania that are found in the gorge include Jacob's ladder, wild pea, and hemlock parsley.