 Past this interchange, PA 72 heads north through forested areas with commercial development as it traverses South Mountain as a three-lane road with two northbound lanes and one southbound lane.PA 72 enters Lebanon County, where it becomes the border between West Cornwall Township and the borough of Cornwall to the east.The route narrows to two lanes and continues through forests before it curves northeast to fully enter Cornwall and come to an interchange with the US 322 freeway bypass of Cornwall.