The southern terminus of the route was at NY 8 in the town of Horicon near the hamlet of Starbuckville.

Across the river, Carl Turner Road, a locally maintained highway, followed a routing parallel to that of NY 9M on the other shore.

Both roads gradually curved northward, mirroring a similar turn in the river's course.

[citation needed] North of Short Street, NY 9M curved back to the northwest, passing Smith Pond and traveling through woodlands as it approached Schroon Lake.

It then crossed over the southern tip of the lake and entered the town of Chester on the opposite bank.