New discoveries: researching prehistoric site distribution in the Allegheny Mountains. Part I

By Chris

The growing importance of the study of the distribution of upland prehistoric sites throughout the vicinity of New York State is reflected in recent professional publications. The increase in State Govt’ requirements for CRM survey for development and the tighter test intervals in both PA and NY has resulted in bigger investigations of these previously ignored landforms. Recent work in NY has Complemented and inspired the continuation of this trend toward looking in new places, in upland settings. Specifically work by Dr. Versaggi and PAF, Hasenstab & Johnson, Carr & Adovasio have used survey data to redefine and refine prehistory in the central Appalachian ridge and valley and plateau. PAF continue to unearth and decipher vital data from prehistoric sites across the fingerlakes uplands. Drs. Carr and Adovasio have expanded the range of the earliest inhabitants of the Americas into the Northeast in PA and NY. While Hasenstab & Johnson have looked specifically at the agricultural development of the Allegheny Plateau during the late Prehistoric period.

This blog was inspired by these reports and others and presents the preliminary results of field investigations within the hills south of Allegheny State Park within the Allegheny National Forest. This upland study involved a selective survey strategy of several hundreds of acres for an Alleghenies project. The survey was surprisingly successful in many ways. The survey covered uplands to be crossed by approximately 50 miles of trails across Northeastern Pennsylvania.

This area was not previously unexamined. Hundreds of acres of the logged forest and roadways had been surveyed. Most of these surveys were small and were confined to the footprint of disturbances only, that usually being the forested slopes or valley floors. Until our recent project in the Spring and Summer of 2005 only a single prehistoric site. This rock-shelter was identified by Robert Dean (Seneca THPO) during his many volunteer surveys of the Alleghenies over the past few decades. This was the only documented prehistoric or indigenous site within miles of the portion of the county covering our survey area.

The survey covered 2,105 acres of the upland forest. The topography including the project area is mountainous with narrow valleys winding through high ridges and scattered plateaus. This area, lying at the northern end of the unglaciated Appalachian chain, had changed over the past 11 millennia from tundra to spruce, to pine and finally hemlock and chestnut forest.

This project area matches only a small portion of the area of potential effect of the trail system, including the trail and the woods within 400 meters. The area of effect would have covered 10s of thousands of acres from this motorized traffic and the greater accessibility to hikers/riders. The ANF couldn’t manage this much of a survey. So a sampling was proposed that would only cover around 2/3rds of the trail with the archaeological reconnaissance survey.

This project was conducted with a sampling design that is regional in scope and based on probabilities for encountering the greatest number of prehistoric sites with the smallest survey area (Binford 1964, Mueller 1975). We were trying to isolate microenvironments particular to the northern portion of the Allegheny Plateau that would have been favorable to prehistoric use and travel. The results of previous studies of prehistoric site distribution within these various environments were consulted. This suggested a low potential for finding any prehistoric sites other than the occasional rock-shelter, however. But based on previously documented patterns an intuitive region-based sample of more productive environments was isolated. These environments in the ANF include benches, ridges, saddles, narrow drainage terraces, the heads of drainages, and rock-shelters. The resulting technique of archaeological inquiry permitted the investigation of cultural systems over a large area within a limited time period and budget while still testing existing hypotheses for prehistoric site distribution.

The project area was divided into three areas corresponding to intuitive levels of potential to contain prehistoric cultural resources divided into high, moderate and low probability areas.

High probability (included 77 acres within the project area) areas are described as:
-relatively level (<10º slope).
-within 30 meters from a permanent or seasonal drainage or seep.
-narrow saddles.
-along plateaus and benches adjacent to large boulders fields and rocky outcrops.

Moderate probability (included 166 acres within the project area) areas are described as:
-relatively level (<10º slope).
-portions of the heads of valleys or hollows that are greater than 30 meters from a drainage or seep.
-narrow ridges adjacent to saddles.

Low probability areas are described as:
-sloping areas near large boulder fields or the heads of drainages.
-relatively level (<10º slope) ridges not adjacent to saddles.

Therefore the sampling strategy for the survey consisted of three methods of surveying:
-50 cm square shovel test excavation at 15 meter intervals within high probability areas.
-50 cm square shovel test excavation at 30 meter intervals within moderate probability areas.
-visual inspection along transects spaced at 30 meter intervals and opportunistic shovel testing within rock-shelters in low probability areas.

Rocky outcrops were scattered along the slopes and the edges of the plateaus throughout the project area. Therefore, it was necessary to establish specific dimension criteria for the identification of a rock-shelter in order to improve the chances of encountering prehistorically occupied shelters. Shovel test units at the 18 rock-shelters tested were spaced at 5 meters intervals within the drip-line. In order to examine deeply buried deposits common to Allegheny rock-shelters, these units were excavated to at least a depth of 50 centimeters below the ground surface regardless of soil type or down to bedrock.

The results of the selective investigation was positive and will be presented in a forthcoming blog. Thanks for reading my blog. If you have questions or comments please write me at

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