 The second general division of the river system of the state includes the basins of the Allegheny, Susquehanna, Delaware, and Hudson.The Allegheny Basin embraces the southerly half of Chautauqua and Cattaraugus counties and the southwest corner of Allegany County.The Allegheny River enters the state from the south in the southeast corner of Cattaraugus County, flows in nearly a semicircle, with its outward curve toward the north, and flows out of the state in the southwest part of the same county.