Eastern U.S. Terrain: Not Mountainous, But Appalachian Boundary

Eastern United States Topography

Contrary to the premise, there are no major mountain ranges in the eastern U.S. proper. The region's topography is predominantly:

• Coastal Plain (Atlantic/Gulf): Flat, low-lying, sedimentary
• Piedmont: Rolling hills, transition zone
• Interior Lowlands: Gentle plains (Midwest)

The Appalachian Boundary

The Appalachian Mountains form the traditional boundary between the eastern and central United States, running from Alabama to Maine. Only in the far northeastern U.S. (Maine, New Hampshire, Vermont, parts of NY) do the Appalachians extend into what's considered the "eastern" region, creating the White Mountains, Green Mountains, and Maine's North Woods.

Key Subranges in the Northeast

• White Mountains (NH) – Mount Washington (6,288 ft)
• Green Mountains (VT)
• Longfellow Mountains (ME)
• Adirondacks (NY) – geologically distinct, not Appalachian

Thus, the Appalachians are the eastern edge of the central U.S., not a range within the eastern U.S., except at the northeastern terminus.