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NY-MA-CT Tripoint Marker

There are a number of areas in the 48 contiguous United States known as tri-state areas where three states either meet at one point (a tripoint) or are in proximity to each other. The best known of the latter type is the New York metropolitan area. Another well known tri-state region is located where Pennsylvania meets Delaware and New Jersey.

The Tri-State area around New York City is where New York, New Jersey, and Connecticut nearly meet. There is no tripoint, however, as Connecticut does not touch New Jersey. The term "tri-state" may also be used to refer to Chicago's tri-state region, commonly referred to as Chicagoland, which includes Illinois, Indiana, and Wisconsin. This tri-state region also does not have a tripoint since Indiana does not touch Wisconsin.

Another example where three states meet are Philadelphia's Delaware Valley and the Pittsburgh tri-State. Pittsburgh's tri-state region includes Pennsylvania, Ohio, and West Virginia, which meet near the Beginning Point of the U.S. Public Land Survey northwest of Pittsburgh. Philadelphia's tri-state area consists of Southeastern Pennsylvania, Southern New Jersey, and Delaware, with a tripoint meeting in the Delaware River near the east end of the Twelve-Mile Arc.

Other large metropolitan areas with a tri-state area include Cincinnati and Memphis.

Smaller tri-state areas include those of Dubuque, Iowa, which spills over into Illinois and Wisconsin; of Quincy, Illinois which includes parts of Missouri and Iowa; Evansville, Indiana, which includes parts of Illinois and Kentucky, and the Huntington (W.V.)-Ashland (Ky.)-Ironton (Oh.) Tri-State region, which incorporates areas of Kentucky, Ohio, and West Virginia. The Quincy, Evansville, and Huntington-Ashland areas are noteworthy for the states included all being separated by rivers.

Also notable, Chattanooga, Tennessee is associated with a nearby tripoint that includes Alabama and Georgia.

The area that includes Washington, D.C. and the nearby parts of Maryland and the Virginias is sometimes loosely referred to as a "tri-state area," although the District of Columbia is not a state.

The "Joplin District", a lead and zinc mining region of Oklahoma, Kansas and Missouri, produced mineral specimens known as "Tri-State" minerals.

Land tripoints [link]

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.^[1] They are:

Water tripoints [link]

Twenty-seven tripoints are under water:

Regions with no Tripoint [link]

The following tri-state areas are also notable, but have no tripoint:

See also [link]

• Phineas and Ferb (an undefined tri-state area is the setting of the series and mentioned in every episode.)
• Four State Area
• Four Corners
• Twin cities (geographical proximity), which includes tri-city

References [link]

1. ^ "Tri State Corners in the United States". Jack Parsell. https://www.bjbsoftware.com/corners/docs/parsell.pdf. 
2. ^ Tri-State Peak at Cumberland Gap National Historical Park
3. ^ Eric Jones. New Hampshire Curiosities. Globe Pequot, 2006. p114-5.

External links [link]

• Tripoint Guide
• The US Tri-Corner Home Page