 PA 25 was realigned to head east from Hegins to Newtown in the 1930s, with the former alignment between Pine Grove and Hegins becoming a relocated PA 125.PA 25 begins at an intersection with US 209 in the borough of Millersburg in Dauphin County, heading northeast on two-lane undivided Johnson Street.The road passes homes and continues into Upper Paxton Township, becoming Berrysburg Road and heading into open agricultural areas with a few residences in the Lykens Valley, a rural valley that is home to an Amish community.