At the top of the mountain, PA 305 crosses into Union Township in Mifflin County and leaves the boundaries of Rothrock State Forest. The route begins to descend the forested mountain, curving to the east. At the base of Stone Mountain, the road turns to the southeast and heads into the Kishacoquillas Valley, an agricultural valley which is home to an Amish community. Here, the route runs through farmland with some residences. PA 305 continues southeast to its eastern terminus at an intersection with PA 655 near the community of Belleville.