Blue Mountain is a ridge that forms the eastern edge of the Appalachian mountain range in the U.S. state of Pennsylvania. It cuts across the eastern half of the state from New Jersey to Maryland, providing a distinct boundary between a number of Pennsylvania's geographical and cultural regions. To its northwest side are the southern and central mountains and valleys, the "coal region," and the Poconos. To its southeast side are the Cumberland Valley, the "capital region," Pennsylvania Dutch Country, and the Lehigh Valley.