Letchworth State Park is a 14,427-acre New York State Park located in Livingston and Wyoming Counties in western Upstate New York. The park is roughly 17 miles long, following the course of the Genesee River as it flows north through a deep gorge and over several large waterfalls. It is located 35 miles southwest of Rochester and 60 miles southeast of B…Letchworth State Park is a 14,427-acre New York State Park located in Livingston and Wyoming Counties in western Upstate New York. The park is roughly 17 miles long, following the course of the Genesee River as it flows north through a deep gorge and over several large waterfalls. It is located 35 miles southwest of Rochester and 60 miles southeast of Buffalo, and spans portions of the Livingston County towns of Leicester, Mount Morris and Portage, as well as the Wyoming County towns of Castile and Genesee Falls.