It was the only state-numbered highway in Maine that was entirely locally maintained.

It headed north along Pond Road heading through a wooded area with no houses or other structures only passing under a set of power lines.

At Morgan Pitch Road, SR 203 curved to the northwest and would remain in this general heading for the remainder of the route.

After crossing Marsh Stream, the highway ended at a Y-intersection with SR 139 west of the center of Brooks.

[2] SR 203 was the only state route in Maine that was designated by the Maine Department of Transportation as a town road for its entire length as opposed to a state highway or a state-aid highway.