Olean is a city in Cattaraugus County, New York, United States. Olean is the largest city in Cattaraugus County and serves as its financial, business, transportation and entertainment center. It is one of the principal cities of the Southern Tier region of New York.The city is surrounded by the town of Olean and is located in the southeastern part of the county. The population was 14,452 at the 2010 census.GeographyOlean is located in southeastern Cattaraugus County at .According to the United States Census Bureau, the city has a total area of 16.0sqkm, of which 15.3sqkm is land and 0.7sqkm, or 4.19%, is water.The city is located where Olean Creek flows into the Allegheny River and by the Southern Tier Expressway . New York State Route 417 passes east–west through the city and intersects New York State Route 16, a north–south highway.HistoryThe first European in the area was possibly Joseph de La Roche Daillon, a missionary and explorer from Canada. La Roche reported on the presence of oil near Cuba, the first petroleum sighting in North America. At that time the area was a part of the territory of the Wenrohronon or Wenro Indians, an Iroquois speaking people. In 1643, the Wenro tribes became the first victims of a series of brutal conflicts known as the Second Beaver War.