The Great Appalachian Valley, also called The Great Valley or Great Valley Region, is one of the major landform features of eastern North America. It is a gigantic trough, including a chain of valley lowlands, and the central feature of the Appalachian Mountains system. The trough stretches about 1,200 miles (1,900 km) from Quebec in the north to Alabama in the south and has been an important north–south route of travel since prehistoric times.
Blue Mountain in the Lehigh Valley region of eastern Pennsylvania
Bald Eagle State Forest in Union County, Pennsylvania
The Appalachian Mountains, often called the Appalachians, are a mountain range in eastern to northeastern North America. The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain. The general definition used is one followed by the United States Geological Survey and the Geological Survey of Canada to describe the respective countries' physiographic regions. The U.S. uses the term Appalachian Highlands and Canada uses the term Appalachian Uplands; the Appalachian Mountains are not synonymous with the Appalachian Plateau, which is one of the provinces of the Appalachian Highlands.
The Appalachian Mountains in the background with Penns Valley in Pennsylvania in the foreground in October 2021
Appalachian Mountains broken down by physiographic division, provinces, and sections
Appalachian Highlands physiographic provinces
Appalachian Uplands of Canada's 13 divisions