The Eastern States Rock Art Research
Association (ESRARA) held its 2022 conference on Oct. 7-8, 2022, in
St. Louis, Missouri. The conference brought together presenters and attendees
from nine states to discuss the documentation, preservation, and interpretation
of rock art sites which included petroglyph (images carved on stone) and
pictograph (images painted or drawn on stone) sites in the Eastern United
States. Pennsylvania was well represented with three presentations focusing on rock
art sites from the Keystone State, which now has over forty petroglyph sites
recorded in its cultural resource site files.
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The logo for the |
A theme throughout the conference was that rock art sites often go unnoticed unless someone is looking for them. One of the presentations focused on Pennsylvania included images and discussion about seemingly forgotten sites and another previously undocumented petroglyph site in the Lower Susquehanna Valley. Located atop a small rock island in the river is carved the figure of a birdman that was previously unknown to researchers.
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A figure with both |
As digital technologies advance so do methods for documenting petroglyph sites. Several presentations at the conference demonstrated the use of 3D modeling using photogrammetry and LiDAR. Photogrammetry software uses images to construct a 3-dimensional model while LiDAR uses specialized equipment to collect data with a laser. A benefit of photogrammetry is that no specialized equipment is needed to collect the data, just a digital camera. Photos are then imported into photogrammetry software and a 3D model created. Unlike archaeological excavation, which is a destructive process, the study of rock art primarily uses non-destructive methods of documentation, and it promotes the preservation of sites where they were created hundreds or even thousands of years ago.
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This birds-eye |
Presenters also discussed new methods of illustrating sites using digital technologies. Referencing the same site as the 3D model above, the image below was created by digitally tracing a high-resolution photograph of the site using a Wacom drawing tablet and Adobe Photoshop. Drawing a site in this format provides a comprehensive method of visualizing subtle detail that has been excluded from previous attempts to map petroglyph/pictograph sites. It also gives the viewer a realistic view of the site at a specific time of day and year. Methods of mapping sites using such media as chalk or other substances are not recommended by conservators.
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An original |
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day-long field trip to Cahokia
Mounds, an UNESCO world heritage site, and two nearby petroglyph
sites. One of these sites, Washington State Park,
provided caution against well-meaning infrastructure improvements that can
damage a site over the long term, as seen below.
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The above images of |
For more information, visit the Eastern States Rock Art Research Association (ESRARA). For more information on Pennsylvania Petroglyphs, view our petroglyph brochure (PDF).
Links and Resources:
American Rock Art Research Association (ARARA)
ARARA is an active community dedicated to rock art preservation, research, and education. Several educational resources can be found on their website, including lesson plans for grades K-9. ARARA hosts frequent web presentations and holds an annual conference. Past web presentations can be found on their YouTube channel.
Eastern States Rock Art Research Association (ESRARA)
ESRARA is a group of dedicated professional and avocational members who focus their attention on rock art located in the Eastern United States.
Society for Pennsylvania Archaeology (SPA)
A community of professional and avocational archaeologists dedicated to the scientific study and conservation of archaeological resources in Pennsylvania and surrounding states. Their 92nd annual conference will be held in Dubois, Pennsylvania on April 14-16, 2023.
Burkett, Ken
2021 The Chickaree Hill Pictograph (36CB28). Pennsylvania Archaeologist. Vol 91(2)
Cadzow, Donald
1932 Petroglyphs [Rock Carvings] in the Susquehanna River near Safe Harbor, Pennsylvania, Safe Harbor Report No. 1. Pennsylvania Historical and Museum Commission, Harrisburg.
Swauger, James
1974 Rock Art of the Upper Ohio Valley. Akademische Druck, Austria.
