The contiguous United States (the 'Lower 48') are divided into physiographic provinces according to their geomorphology. Geomorphology refers to the physical features and processes of landforms, and their relation to geologic structures. The climate, underlying geology, and the geologic history of an area affect the modern topography. Some areas have been scraped flat by glaciers, others are dominated by towering mountains, and still others are subject to changing sea levels and coastal processes.
Every province has its own beauty, and its own cultural and geologic heritage highlighted by the National Park System. From the Statue of Liberty to Everglades National Park, and the Grand Canyon to Mount Rainier, the diverse and rich bounty of our country's landscape awaits your exploration.