New York–Pennsylvania border

The New York–Pennsylvania border is the state line between the U.S. states of New York and Pennsylvania. It has three sections:

The survey of the 42nd parallel north was carried out in 1785-6 and accepted by the two states in 1787. The surveying technique that was used by the surveyors was not of the greatest quality, and as such, this boundary wanders a bit on both sides of the true parallel. The 82nd mile stone was used as the starting point of the Preemption Line defined in the Treaty of Hartford in 1786 to separate Massachusetts and New York State land claims in Western New York.

The survey of the Erie Triangle boundary was by the top surveyor in the USA of the time, Andrew Ellicott in 1789.

The starting point of the 42nd parallel north line is in the Delaware River at the northeast corner of Wayne County, PA at 41°59′57″ N, 75°21′35″ W WGS 84. The initial surveyor's monument is just west of Faulkner Road at 41°59′58″ N, 75°21′43″ W.

The corner point of the Erie Triangle in modern coordinates is 41°59′55″ N, 79°45′43″ W.

The distance along the east-west line is approximately 363.49 km (225.86 statute miles)

The counties that surround the east-west line are known collectively as the Twin Tiers.

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