Physiographic regions of the United States

The physiographic regions of the contiguous United States comprise 8 divisions, 25 provinces, and 85 sections.

[1] The system dates to Nevin Fenneman's report Physiographic Divisions of the United States, published in 1916.

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.

USGS map of the eight physiographic divisions of the contiguous United States.
1946 Map published by USGS documenting the work of Fenneman's 1915-16 committee of the American Association of Geographers.
USGS map colored by paleogeological areas and demarcating the sections of the U.S. physiographic regions: Laurentian Upland (area 1), Atlantic Plain (2-3), Appalachian Highlands (4-10), Interior Plains (11-13), Interior Highlands (14-15), Rocky Mountain System (16-19), Intermontane Plateaus (20-22), & Pacific Mountain System (23-25)
The legend of paleogeological color also depicts topographic terrain.