Allegany County, New York

Allegany County
Allegany County Courthouse
Location within the U.S. state of New York
New York's location within the U.S.
Coordinates: 42°13′59″N 78°01′34″W / 42.232937°N 78.026093°W / 42.232937; -78.026093
Country United States
State New York
Founded1806
Named afterLenape name for the Allegheny River
SeatBelmont
Largest townWellsville
Government
  County ChairmanPhilip Stockin
Area
  Total
1,034 sq mi (2,680 km2)
  Land1,029 sq mi (2,670 km2)
  Water5.1 sq mi (13 km2)  0.5%
Population
 (2020)
  Total
46,456
  Estimate 
(2024)
47,299
  Density49/sq mi (19/km2)
Time zoneUTC−5 (Eastern)
  Summer (DST)UTC−4 (EDT)
Congressional district23rd
Websitewww.alleganyco.gov

Allegany County is a county in the U.S. state of New York. As of the 2020 census, the population was 46,456. Its county seat is Belmont. Its name derives from a Lenape word, applied by European-American settlers of Western New York State to a trail that followed the Allegheny River; they also named the county after this. The county is part of the Western New York region of the state.

The county is bisected by the Genesee River, flowing north to its mouth on Lake Ontario. During the mid-nineteenth century, the Genesee Valley Canal was built to link southern markets to the Great Lakes and Mohawk River. The county was also served by railroads, which soon superseded the canals in their capacity for carrying freight. Part of the Oil Springs Reservation, controlled by the Seneca Nation, is located in the county.