The western terminus of the route is at an intersection with NY 66 in the town of North Greenbush.

Its eastern terminus is at a junction with NY 351 in the hamlet of Poestenkill within the town of the same name.

The highway proceeds eastward into the town of Poestenkill, passing to the south of residential homes and Moules Pond.

Route 355 is known for most of its length as Cooper Hill Road as it heads eastward towards downtown Poestenkill.

From there, NY 154 continued east to the hamlet of Poestenkill, where it ended at a junction with Round Top and White Church Roads.