East of Syracuse, the route passes through a narrow portion of the town of Onondaga and the hamlet of Southwood before entering the adjacent town of DeWitt. It continues east, serving Clark Reservation State Park as it heads toward the community of Jamesville, located at the northern end of the Jamesville Reservoir on Butternut Creek. Here, NY 173 intersects NY 91 in the center of the hamlet. Past Jamesville, the homes that had lined the highway give way to open areas to the south and large quarries to the north. The route passes north of the Onondaga County Correctional Facility just east of Jamesville.