Physical Regions of the United States and Canada

The physical geography of the United States and Canada is organized into a series of physiographic provinces first systematically classified by geographer Nevin M. Fenneman in his 1928 paper "Physiographic Divisions of the United States," a scheme later extended northward to describe Canada's parallel structure. Moving from east to west, the continent presents a broad Atlantic and Gulf Coastal Plain, the ancient folded Appalachian Mountains, an interior lowland of plains and till plains, the Great Plains rising gradually toward the Rockies, the young and rugged Rocky Mountain cordillera, an intermontane region of basins and plateaus, and finally the Pacific coastal ranges. This west-to-east sequence broadly reflects a west-to-east decrease in geological youth and relief, though the ancient Canadian Shield in the northeast breaks that pattern entirely.