Summerdale is located at 40°18'41" North, 76°55'54" West, on the west side of U.S. Route 11/15 and the south side of Interstate 81. These two highways interchange just north of Summerdale.
Summerdale was founded in 1909. As people from Harrisburg came over the river during the summers, a dance hall was erected to support their need to party, thus, starting the town of Summerdale. In 2009, Summerdale held a Centennial Celebration. There was a parade, games, and a year-long celebration dedicated to the small town of Summerdale.