Understanding the difference between conterminous and contiguous when describing the United States is more than a linguistic exercise; it is a matter of precise geographic definition. For cartographers, historians, and anyone analyzing data related to the nation’s landmass, these terms specify whether the discussion includes Alaska and Hawaii or focuses solely on the 48 adjoining states.
The Definition of Conterminous United States
The term "conterminous" refers to areas that share a common boundary. In the context of the United States, the conterminous country specifically describes the 48 states that are physically connected, excluding the non-adjacent states of Alaska and Hawaii. This term is favored in technical and cartographic fields because it implies a shared border without gaps, providing a precise way to delineate the main body of the nation.
The Definition of Contiguous United States
Contiguous, by definition, means things that are touching or in actual contact. When applied to the US, the contiguous United States carries the same geographic meaning as the conterminous United States: the 48 states where each piece is connected to another. While some style guides might suggest subtle differences in connotation, in modern geographic usage, contiguous is effectively a synonym for conterminous in this context, both pointing to the connected mainland.
Key Distinction from Non-Conterminous States
Alaska: Purchased from Russia in 1867, it is separated from the lower 48 by Canada, making it non-conterminous.
Hawaii: An island chain in the Pacific Ocean, Hawaii is geographically isolated and therefore not part of the conterminous zone.
US Territories: Territories such as Puerto Rico and Guam are also non-conterminous, as they are separated by water from the mainland and from each other.
Why These Terms Matter in Analysis
Using the precise term "conterminous" is vital when conducting demographic research or climate studies. If a report states that the population density is X per square mile, it is critical to know if that figure includes Alaska and Hawaii. Including these vast but sparsely populated states would dramatically skew the average, making the data less useful for understanding the living conditions of the majority of Americans.
Visual Representation and Common Misconceptions
Maps of the United States often create visual confusion. Many feature the standard rectangular layout that squeezes the curved surface of the earth into a flat image, inadvertently giving the impression that Alaska is comparable in size to the conterminous states. In reality, Alaska is massive, and when viewed on a map centered on the Pacific, the disconnect between Hawaii and the mainland becomes visually obvious. Recognizing the conterminous zone helps viewers look past these cartographic distortions.
Application in Logistics and Infrastructure
For transportation and logistics, the conterminous United States represents a contiguous network of roads and rail lines. While the Alaska Highway connects Alaska to the network, and ferries link Hawaii, the primary flow of goods occurs within the connected 48 states. The term helps logistics companies define shipping zones, calculate transit times, and establish infrastructure investment priorities based on connected landmass rather than political boundaries.
