 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 . 
