The southern terminus of the route is at NY 3 in the Hounsfield hamlet of Baggs Corner, located 7 miles (11 km) west of downtown Watertown.

A state-maintained continuation of County Route 66 (CR 66), NY 180 runs northeast through the wide fields of Hounsfield, passing east of the Black River Bay, and after bending north, the route passes west of Watertown International Airport.

The route makes a bend to the northeast and enters the hamlet of Limerick, where it crosses a junction with NY 12E.

Now paralleling the Perch River, NY 180 runs northeast through the fields, reaching a junction with CR 54 (Depauville Road).

A distance into Orleans, the route enters the hamlet of Stone Mills, a residential community in which NY 180 serves as the main thoroughfare.

The route soon bends northeast again, passing Grove Cemetery as it enters the hamlet of La Fargeville.

Paralleling the Chaumont River, NY 180 enters La Fargeville as the two-lane Main Street.

[10][11] The other independent portion of NY 179 from Chaumont to Depauville—the route's original alignment—is now maintained by Jefferson County as CR 179.