PHYSIOGRAPHIC REGIONS OF THE LOWER 48 UNITED STATES after Fenneman (1928)

LAURENTIAN UPLAND

1. Superior Upland

ATLANTIC PLAIN

2. Continental Shelf (not on map) 
3. Coastal Plain
     a. Embayed section
     b. Sea Island section
     c. Floridian section
     d. East Gulf Coastal Plain 
     e. Mississippi Alluvial Plain 
     f. West Gulf Coastal Plain

APPALACHIAN HIGHLANDS

4. Piedmont province
     a. Piedmont Upland
     b. Piedmont Lowlands 
5. Blue Ridge province
     a. Northern section
     b. Southern section 
6. Valley and Ridge province
     a. Tennessee section 
     b. Middle section
     c. Hudson Valley
7. St. Lawrence Valley
     a. Champlain section
     b. Northern section (not on map) 
8. Appalachian Plateaus province
     a. Mohawk section
     b. Catskill section
     c. Southern New York section
     d. Allegheny Mountain section 
     e. Kanawha section
     f. Cumberland Plateau section 
     g. Cumberland Mountain section
9. New England Province
     a. Seaboard Lowland section
     b. New England Upland section 
     c. White Mountain section
     d. Green Mountain section
     e. Taconic section
10. Adirondack province

INTERIOR PLAINS

11. Interior Low Plateaus
     a. Highland Rim section 
     b. Lexington Plain
     c. Nashville Basin
12. Central Lowland
     a. Eastern Lake section
     b. Western Lake section
     c. Wisconsin Driftless section 
     d. Till Plains
     e. Dissected Till Plains
     f. Osage Plains
13. Great Plains province
     a. Missouri Plateau, glaciated
     b. Missouri Plateau, unglaciated
     c. Black Hills
     d. High Plains
     e. Plains Border
     f. Colorado Piedmont
     g. Raton section
     h. Pecos Valley
     i. Edwards Plateau
     k. Central Texas section

INTERIOR HIGHLANDS

14. Ozark Plateaus
     a. Springfield-Salem plateaus
     b. Boston “Mountains” 
15. Ouachita province
     a. Arkansas Valley
     b. Ouachita Mountains

ROCKY MOUNTAIN SYSTEM

16. Southern Rocky Mountains
17. Wyoming Basin
18. Middle Rocky Mountains 
19. Northern Rocky Mountains

INTERMONTANE PLATEAUS

20. Columbia Plateau
     a. Walla Walla Plateau 
     b. Blue Mountain section 
     c. Payette section
     d. Snake River Plain
     e. Harney section
21. Colorado Plateaus
     a. High Plateaus of Utah
     b. Uinta Basin
     c. Canyon Lands
     d. Navajo section
     e. Grand Canyon section 
     f. Datil section
22. Basin and Range province 
     a. Great Basin
     b. Sonoran Desert
     c. Salton Trough
     d. Mexican Highland 
     e. Sacramento section

PACIFIC MOUNTAIN SYSTEM

23. Cascade-Sierra Mountains
     a. Northern Cascade Mountains 
     b. Middle Cascade Mountains 
     c. Southern Cascade Mountains 
     d. Sierra Nevada
24. Pacific Border province 
     a. Puget Trough
     b. Olympic Mountains
     c. Oregon Coast Range
     d. Klamath Mountains
     e. California Trough
     f. California Coast Ranges 
     g. Los Angeles Ranges