United States Geological Survey (USGS). (n.d.). Topographic Maps (DRG) for Pennsylvania 1:24,000 - UTM. State of Pennsylvania. http://www.pasda.psu.edu/uci/DataSummary.aspx?dataset=78

Available from: https://geo.btaa.org/catalog/2a297aa5-7bd1-4781-8705-6f36c7cdce16