The Neversink River (also called Neversink Creek in its upper course) is a 55-mile-long (89 km) tributary of the Delaware River in southeastern New York in the United States. The name of the river comes from the corruption of an Algonquian language phrase meaning "mad river." In the 1890s Theodore Gordon expertly matched dry fishing flies to actual insects. Edward Ringwood Hewitt conducted research on insect and flies from his property above the town of Neversink. As a result, the Neversink River is considered by many to be the birthplace of American dry fly fishing.