"[citation needed] The Neversink River is considered by many to be the birthplace of American dry fly fishing.

[2] The Neversink's main flow begins just south of the border between present-day Ulster and Sullivan counties, where the east and west branches of the river join near the hamlet of Claryville.

The west branch is joined by several major tributaries, such as Biscuit Brook and Pigeon Creek at Frost Valley YMCA in the town of Denning, Ulster County.

At this confluence with the Delaware, the Tri-States Monument marks the tripoint of the borders of New York, New Jersey, and Pennsylvania; Interstate 84 bridge passes over this point.

Edward Ringwood Hewitt conducted research on insect and flies from his property above the town of Neversink.

Their work led to the river gaining a reputation as birthplace of American dry fly fishing.

[2] The river is home to other fish species such as smallmouth bass, carp, sucker, bluegill, American eel, and lampreys; and a diverse range of flora and fauna.

The Delaware & Hudson Canal crossed the river at Cuddebackville by an early aqueduct bridge designed by John Roebling and built in 1851.