Old Saw Mill River Road begins at Grasslands Road (NY 100C) near its interchange with Saw Mill River Road (NY 9A). It runs west through Hawthorne as a four-lane divided road with a grass median.

Photos taken October 2020.

The median ends.

Photos taken October 2020.

There is an interchange with the Saw Mill Parkway. There are two overpasses here. The first is the North County Trailway, a rail trail, while the second is the parkway. Old Saw Mill River Road ends here. Nepperan Road, a local street, is straight ahead.

Photos taken October 2020.