Tri-state area

Tri-state area is an informal term in the eastern contiguous United States for any of several regions associated with a particular town or metropolis that, with adjacent suburbs, lies across three states. Some of these involve a state boundary tripoint. Other tri-state areas have a more diffuse population that shares a connected economy and geography—especially with respect to geology, botany, or climate. The term "tri-state area" is often present in films, radio and television commercials.
Tri-state areas.
The Quincy, Evansville, and Huntington–Ashland areas are noteworthy for the states included all being separated by rivers.
Tripoints.
Land.
Of the 62 points in the United States where three and only three states meet (each of which may be associated with its own tri-state area), 35 are on dry land and 27 are in water.
Regions with no tripoint.
The following tri-state areas are also notable, but have no tripoint: