# Physiographic regions of the United States

The physiographic regions of the contiguous United States comprise 8 divisions, 25 provinces, and 85 sections. The system dates to Nevin Fenneman's report Physiographic Divisions of the United States, published in 1916. The map was updated and republished by the Association of American Geographers in 1928. The map was adopted by the United States Geological Survey by publication in 1946.
The classification hierarchy used in the 1916 publication of the American Association of Geographers was division/province/section/subsection. The use of province in this hierarchy undoubtedly confounded the effort to develop a physiographical map consistent across the North American continent since Canada used province as the term for its first-level political subdivision. Province in Canada is a loose analogy for state in the US, and obviously would create great confusion if the same word was used in two vastly different geographical classifications. As late as 1914, the terminology used by an AAG publication used the term "natural region" as the basic denomination of physiography. That work showed 22 examples of how geographers had published works classifying North America into what had been defined as natural regions. Most included all of North America without regard to political subdivision.
Fenneman expanded and presented a derivative of this system more fully in two books, Physiography of western United States (1931), and Physiography of eastern United States (1938).

## Physiographic divisions

| Division | Province | Section |
| I. Laurentian Upland | 1. Superior Upland | 1. Superior Upland |
| II. Atlantic Plain | 2. Continental Shelf (not on map) | 2. Continental Shelf (not on map) |
| II. Atlantic Plain | 3. Coastal Plain | 3a. Embayed section |
| II. Atlantic Plain | 3. Coastal Plain | 3b. Sea Island section |
| II. Atlantic Plain | 3. Coastal Plain | 3c. Floridian section |
| II. Atlantic Plain | 3. Coastal Plain | 3d. East Gulf Coastal Plain |
| II. Atlantic Plain | 3. Coastal Plain | 3e. Mississippi Alluvial Plain |
| II. Atlantic Plain | 3. Coastal Plain | 3f. West Gulf Coastal Plain |
| III. Appalachian Highlands | 4. Piedmont | 4a. Piedmont Upland |
| III. Appalachian Highlands | 4. Piedmont | 4b. Piedmont Lowlands |
| III. Appalachian Highlands | 5. Blue Ridge province | 5a. Northern section |
| III. Appalachian Highlands | 5. Blue Ridge province | 5b. Southern section |
| III. Appalachian Highlands | 6. Valley and Ridge province | 6a. Tennessee section |
| III. Appalachian Highlands | 6. Valley and Ridge province | 6b. Middle section |
| III. Appalachian Highlands | 6. Valley and Ridge province | 6c. Hudson Valley |
| III. Appalachian Highlands | 7. St. Lawrence Valley | 7a. Champlain section (dividing line undefined in 1946 map) |
| III. Appalachian Highlands | 7. St. Lawrence Valley | 7b. Northern section (dividing line undefined in 1946 map) |
| III. Appalachian Highlands | 8. Appalachian Plateaus province | 8a. Mohawk section |
| III. Appalachian Highlands | 8. Appalachian Plateaus province | 8b. Catskill section |
| III. Appalachian Highlands | 8. Appalachian Plateaus province | 8c. Southern New York section |
| III. Appalachian Highlands | 8. Appalachian Plateaus province | 8d. Allegheny Plateau section |
| III. Appalachian Highlands | 8. Appalachian Plateaus province | 8e. Kanawha section |
| III. Appalachian Highlands | 8. Appalachian Plateaus province | 8f. Cumberland Plateau section |
| III. Appalachian Highlands | 8. Appalachian Plateaus province | 8g. Cumberland Mountain section |
| III. Appalachian Highlands | 9. New England Province | 9a. Seaboard Lowland section |
| III. Appalachian Highlands | 9. New England Province | 9b. New England Upland section |
| III. Appalachian Highlands | 9. New England Province | 9c. White Mountain section |
| III. Appalachian Highlands | 9. New England Province | 9d. Green Mountain section |
| III. Appalachian Highlands | 9. New England Province | 9e. Taconic section |
| 10. Adirondack province ||
| IV. Interior Plains | 11. Interior Low Plateaus | 11a. Highland Rim |
| IV. Interior Plains | 11. Interior Low Plateaus | 11b. Lexington Plain |
| IV. Interior Plains | 11. Interior Low Plateaus | 11c. Nashville Basin |
| IV. Interior Plains | 12. Central Lowland | 12a. Eastern Lake |
| IV. Interior Plains | 12. Central Lowland | 12b. Western Lake |
| IV. Interior Plains | 12. Central Lowland | 12c. Wisconsin Driftless |
| IV. Interior Plains | 12. Central Lowland | 12d. Till Plains |
| IV. Interior Plains | 12. Central Lowland | 12e. Dissected Till Plains |
| IV. Interior Plains | 12. Central Lowland | 12f. Osage Plains |
| IV. Interior Plains | 13. Great Plains | 13a. Missouri Plateau (glaciated) |
| IV. Interior Plains | 13. Great Plains | 13b. Missouri Plateau (unglaciated) |
| IV. Interior Plains | 13. Great Plains | 13c. Black Hills |
| IV. Interior Plains | 13. Great Plains | 13d. High Plains |
| IV. Interior Plains | 13. Great Plains | 13e. Plains Border |
| IV. Interior Plains | 13. Great Plains | 13f. Colorado Piedmont |
| IV. Interior Plains | 13. Great Plains | 13g. Raton section |
| IV. Interior Plains | 13. Great Plains | 13h. Pecos Valley |
| IV. Interior Plains | 13. Great Plains | 13i. Edwards Plateau |
| IV. Interior Plains | 13. Great Plains | 13j. Central Texas |
| V. Interior Highlands | 14. Ozark Plateaus | 14a. Springfield-Salem plateaus |
| V. Interior Highlands | 14. Ozark Plateaus | 14b. Boston Mountains |
| V. Interior Highlands | 15. Ouachita province | 15a. Arkansas Valley |
| V. Interior Highlands | 15. Ouachita province | 15b. Ouachita Mountains |
| VI. Rocky Mountain System | 16. Southern Rocky Mountains | 16. Southern Rocky Mountains |
| 17. Wyoming Basin ||
| 18. Middle Rocky Mountains ||
| 19. Northern Rocky Mountains ||
| VII. Intermontane Plateaus | 20. Columbia Plateau | 20a. Walla Walla Plateau |
| VII. Intermontane Plateaus | 20. Columbia Plateau | 20b. Blue Mountain section |
| VII. Intermontane Plateaus | 20. Columbia Plateau | 20c. Payette section |
| VII. Intermontane Plateaus | 20. Columbia Plateau | 20d. Snake River Plain |
| VII. Intermontane Plateaus | 20. Columbia Plateau | 20e. Harney section |
| VII. Intermontane Plateaus | 21. Colorado Plateaus | 21a. High Plateaus of Utah |
| VII. Intermontane Plateaus | 21. Colorado Plateaus | 21b. Uinta Basin |
| VII. Intermontane Plateaus | 21. Colorado Plateaus | 21c. Canyon Lands |
| VII. Intermontane Plateaus | 21. Colorado Plateaus | 21d. Navajo section |
| VII. Intermontane Plateaus | 21. Colorado Plateaus | 21e. Grand Canyon section |
| VII. Intermontane Plateaus | 21. Colorado Plateaus | 21f. Datil section |
| VII. Intermontane Plateaus | 22. Basin and Range Province | 22a. Great Basin section |
| VII. Intermontane Plateaus | 22. Basin and Range Province | 22b. Sonoran Desert |
| VII. Intermontane Plateaus | 22. Basin and Range Province | 22c. Salton Trough |
| VII. Intermontane Plateaus | 22. Basin and Range Province | 22d. Mexican Highland |
| VII. Intermontane Plateaus | 22. Basin and Range Province | 22e. Sacramento section |
| VIII. Pacific Mountains | 23. Cascade-Sierra Mountains | 23a. Northern Cascade Mountains |
| VIII. Pacific Mountains | 23. Cascade-Sierra Mountains | 23b. Middle Cascade Mountains |
| VIII. Pacific Mountains | 23. Cascade-Sierra Mountains | 23c. Southern Cascade Mountains |
| VIII. Pacific Mountains | 23. Cascade-Sierra Mountains | 23d. Sierra Nevada |
| VIII. Pacific Mountains | 24. Pacific Border province | 24a. Puget Trough |
| VIII. Pacific Mountains | 24. Pacific Border province | 24b. Olympic Mountains |
| VIII. Pacific Mountains | 24. Pacific Border province | 24c. Oregon Coast Range |
| VIII. Pacific Mountains | 24. Pacific Border province | 24d. Klamath Mountains |
| VIII. Pacific Mountains | 24. Pacific Border province | 24e. California Trough |
| VIII. Pacific Mountains | 24. Pacific Border province | 24f. California Coast Ranges |
| VIII. Pacific Mountains | 24. Pacific Border province | 24g. "Los Angeles Ranges—(Transverse Ranges)" |
| 25. Lower California province—(Peninsular Ranges) ||