NY 55A proceeds northeast through the Catskill State Park, and alongside Chestnut Creek, before bending eastward through Neversink.

NY 55A remains mostly wooded as it begins running alongside the Rondout Reservoir as a two-lane road maintained by New York City.

Passing south of several residences, NY 55A makes a gradual bend alongside the reservoir, making a stretch north past some reservoir facilities before intersecting with BWS Road, a connector to County Route 153 (CR 153; Sundown Road), which heads north to Sundown in Ulster County.

[4] After CR 46, NY 55A crosses a small part of the reservoir, paralleling the waterway past dense woods in Wawarsing.

[4] When NY 55 was assigned as part of the 1930 renumbering of state highways in New York, it was routed along the northern bank of Rondout Creek between the hamlets of Grahamsville and Lackawack.