The route was assigned in 1980 after the section of Thompson Road between NY 290 and Carrier Circle was acquired by the state of New York.

As Thompson Road, NY 635 heads north and connects to I-690 via the full cloverleaf interchange that comprises exit 16.

Just past I-690, NY 635 crosses over the Peat Street Runner, a CSX Transportation railroad spur that largely parallels I-690 into downtown Syracuse, prior to intersecting Burnet Avenue, a street connecting NY 635 to the nearby village of East Syracuse.

The road also acts as a divider between the residential neighborhoods of eastern Syracuse and the industrial factories situated along CSX Transportation's Mohawk Subdivision rail line in DeWitt.

From this point north to its terminus at Carrier Circle, NY 635 is surrounded completely by commercial and industrial properties, including the sprawling Carrier Corporation complex just south of the circle.