The Susquehanna River is almost 450 miles in length but has one unique attraction. Starting in the vicinity of Washington Boro, south to the headwaters of the Chesapeake Bay, Petroglyphics or Rock Carvings by Native Americans can be found.
Many petroglyphs are located near the mouth of the Conestoga River at Safe Harbor. On loan from the Pennsylvania Historical and Museum Commission, Blue Rock Heritage Center is proud to display three such petroglyphs removed from the Susquehanna River before the construction of the Safe Harbor Hydroelectric Dam in 1931.
There are nearly 30 sites recorded in the Ohio Valley although most of these are represented by small groups of images. In contrast, the lower Susquehanna River has the highest concentration of petroglyphs in the Northeast with only 10 sites but probably more than 1000 separate carvings. These are found within a 23-mile stretch running through southern Lancaster County to just below the Mason-Dixon Line. Because of the construction of hydroelectric projects on that portion of the Susquehanna, many of these petroglyphs have been submerged or removed for preservation.
It is interesting that there are very few examples in the Upper Susquehanna drainage or the entire Delaware drainage. There is probably a culturally determined geographical distribution to petroglyphs.
Certain symbols are common on Native American petroglyphs in Pennsylvania. Naturalistic designs include humans, animals, and birds, their footprints and tracks. Other, more symbolic designs include circles, spirals, and dots (cupules), as well as figures that can be described as human or animal-like but changed (anthropomorphic or zoomorphic), or even part animal, part human. Still, other designs represent conventionalized religious, mythological, or supernatural symbols utilized throughout a large geographic and cultural area, such as manifestations of the Algonquian "Great Spirit" or Manitou - Thunderbirds (Pinasiwuk), Bear (Makwa), Wolf (Myeengun), Great Lynx, or Water Panther (Mishipizheu), or Horned Snake (Ginebik). There were many different Native American groups in Pennsylvania and their belief systems varied considerably. The meaning of a symbol to one group may have been very different from another group and some tribes may not have used petroglyphs at all.