Did you know that the Lower Susquehanna Valley,
approximately 50 miles south of Harrisburg, Pennsylvania, is home to one of the
largest concentrations of prehistoric petroglyphs in the Northeastern United
States?
Petroglyphs are a form of rock art in which images are
pecked or carved into the surface of a rock. In the case of Pennsylvania’s
petroglyphs, rocky outcrops along rivers were prime locations where these images
were created. Petroglyphs can be found across Pennsylvania and styles vary
widely depending upon the area in which they were created. Nearly all the petroglyphs
recorded in Pennsylvania (42 sites at time of writing) are associated with
rivers. Waterways were, and still are, significant features of the natural
landscape that have shaped where people lived and how they traveled since long
before the first Europeans settled in this area.
The distribution and
various styles of petroglyphs in Pennsylvania.
Image: PHMC
Petroglyphs Brochure
The petroglyphs south of Harrisburg, PA (numbers 8 and 9 on
the above map) are particularly special due to their location in the center of
the nearly mile-wide Susquehanna River. Some groups of petroglyphs in this
area, such as those on Walnut Island and nearby Creswell rock were submerged
underwater when the Safe Harbor Dam was constructed in the early 1930s. Other
sites farther downstream such as Big and Little Indian Rock are accessible only
by boat, a feature that has no doubt helped preserve the numerous rock carvings
that were made by the prehistoric people who once inhabited this river valley.
It is difficult for us to imagine the vastly different
landscape of the Susquehanna River prior to the construction of railroads and
hydro-electric dams. The river was at one time filled with rocky outcrops,
small islands, and numerous rapids carved by the ancient waters of the
Susquehanna, one of the oldest rivers in the world. The riverscape prior to the
construction of the Safe Harbor Dam is reflected in photos taken prior to the
dam’s construction, as well as by maps made by various surveyors during the 19th
century.
A composite image of the Susquehanna River before and after
construction of the Safe Harbor Dam. Walnut Island is in the group of islands
on the left side of the upper image.
(top image: Scott’s Map of Lancaster County,
Library of Congress; lower image: Google Earth)
In 1930-1931, an expedition led by Donald Cadzow documented
four petroglyph sites in the Safe Harbor area where Conestoga Creek flows into
the Susquehanna River: Little Indian Rock, Big Indian Rock, Walnut Island (now submerged),
and Creswell Rock (now submerged). The team photographed and drew the
petroglyphs of Walnut Island and Creswell Rock before ultimately drilling the
petroglyphs from the surrounding rock on which they were created and transporting
them to the State Museum of Pennsylvania. Four of the petroglyphs from Walnut
Island are on permanent display at the State Museum’s Archaeology Gallery in
Harrisburg, and another four panels are on display at the Conestoga Area
Historical Society Museum in Conestoga, PA. The remainder of the petroglyph
panels removed from Walnut Island and Creswell Rock remain in storage at the
State Museum of Pennsylvania.
The Petroglyphs on
Walnut Island were traced and photographed before being drilled from the
surrounding bedrock. The original section of rock with the pecked image is on
display at the State Museum of Pennsylvania’s Archaeology Gallery. (Image:
PHMC)
Like much of the archaeology performed during the first half
of the 20th century, documentation and collection practices fall
short of today’s standards. Although Cadzow and his team recognized the
importance of the individual images, other information, such as the exact directional
orientation of the glyphs and the shape and nature of surrounding rock
formations, was largely neglected. Additionally, some fruits of their efforts,
such as creating casts of the petroglyphs, have been discarded in the decades
since the work was undertaken. The documentation that exists today falls short
of depicting the full stunning beauty of a place that no doubt held special
significance to the people who created these images.
Donald Cadzow’s map
of petroglyphs on Walnut Island. The image panels depicted on this map are the
best evidence researchers have of their original locations on the island.
(image: Cadzow 1934, PHMC)
Many of the petroglyphs located on Walnut Island bear little
resemblance to the petroglyphs of other rock art sites within the Northeastern
United States, and researchers have long pondered their origins. Other sites
near Safe Harbor, such as Little
Indian Rock and Big Indian Rock are similar in style to petroglyph sites
attributed to Algonkian groups which inhabited much of the Northeast and Canada
during Woodland and Late Prehistoric times.
While the meaning of petroglyphs is still largely unknown, advances
have been made in understanding their significance as places of teaching or for
communing with spirits who were believed to inhabit sacred locations associated
with rocky outcrops and water. Some believe that the petroglyphs are
reflections of the sky above.
One of the abstract
groups of petroglyphs on Walnut Island. This rock outcrop provided a view of
the river looking towards Lancaster County. (image: PHMC)
Donald Cadzow’s report of his expedition is published as a
book under the title Petroglyphs in the
Susquehanna River near Safe Harbor, Pennsylvania. It is available for
purchase from the PA
Heritage book store.
If you visit a petroglyph site, there are steps that you can
take to help preserve this fragile and non-renewable resource for future
generations. Researchers today have no way of knowing what techniques may be
developed in the future that could contribute to the understanding of these
ancient writings.
The following guidelines for visiting petroglyph sites are
adopted from the National Park Service:
-
Do not touch the petroglyphs, even small amounts
of oils from your hands can darken and destroy the carved images
-
Photograph and sketch the images, but avoid
taking rubbings which can hasten the deterioration of the petroglyphs. The best
time of day for viewing petroglyphs is early morning or evening, when the Sun
is low on the horizon.
-
Do not introduce any foreign substance to the rock
surface such as paint or chalk, these actions can damage the image.
-
Do not repeck, recarve or deface the images in
any way, these actions destroy the original image. Many rock art sites have
been destroyed by the addition of historic graffiti.
Petroglyphs in Pennsylvania, videos produced by the PHMC:
Additional
information on petroglyphs is available through our web site:
Additional Resources:
Diaz-Granados, Carol, and James R.
Duncan, eds. The rock-art of eastern North America: Capturing Images
and Insight. Vol. 45879. University of Alabama Press, 2004.
Cadzow, Donald A. Petroglyphs
Rock Carvings in the Susquehanna River Near Safe Harbor. Pennsylvania...
Vol. 3. No. 1. Pennsylvania Historical Commission, 1934.
Lenik, Edward J. Making
pictures in stone: American Indian rock art of the Northeast. University of
Alabama Press, 2009.
Vastokas, Joan M., and Romas K.
Vastokas. Sacred art of the Algonkians: A
study of the Peterborough Petroglyphs. Mansard Press, 1973.
Carr, Kurt W. and Nevin, Paul A., Advanced Technology Rubs Ancient Past. Pennsylvania
Heritage, Vol. XXXIV, No. 4, Fall 2008 (http://www.phmc.state.pa.us/portal/communities/pa-heritage/advanced-technology-rubs-ancient-past.html)
