The route proceeded northward, overlapping NY 321 through the lakeside village and into the surrounding town of Skaneateles, where it became State Street Road.

Once in Skaneateles, the surroundings became mostly rural ahead of an intersection with the Old Seneca Turnpike.

[4][5] West of Camillus, NY 5 and NY 20SY passed to the north of the West Hill Golf and Croquet Club before veering to the southeast as the highway approached the village of Camillus and the edge of a valley surrounding Ninemile Creek that contains the village.

The routes continued on, passing through the town of Geddes before entering the city of Syracuse.

The two routes met the southern terminus of NY 433 at Midler Avenue before passing north of LeMoyne College and exiting the city of Syracuse.

[5][6] The High Bridge Road portion of NY 20SY largely served as a southwestern bypass of Fayetteville.

[5][6] The two routes converged once more, following Fayette Street into the village of Manlius.

As Cazenovia Road, the route served Buellville and Oran, two small creekside hamlets in the town of Pompey.

Roughly 4 miles (6.4 km) southeast of Manlius, Limestone Creek and the three-route overlap split, with the creek proceeding south through a valley known as Pompey Hollow and the highway continuing into Madison County and the town of Cazenovia within.

[4][5] NY 20SY was assigned in 1951[2] as an alternate route of US 20 in the Syracuse area.