The southern terminus is an intersection with PA 74 and Township Route 4026 (Old York Road) in Rossville.

The route continues to form the northwestern boundary of the state park, passing a few homes and fields.

Upon reaching Maytown, PA 177 leaves the state park and turns north through more hilly forests.

Upon crossing PA 382, the route enters the borough of Lewisberry and becomes Market Street as it is lined with homes.

After leaving Lewisberry, PA 177 continues northeast into Newberry Township and becomes Potts Hill Road as it passes through farmland with some residences.

The route descends the hill into a mix of farms and homes, with the road fully entering Fairview Township.

[7][8] With the creation of the U.S. Highway System in 1926, US 111 became concurrent with PA 4 on Old York Road, which was paved.