Saluda Hydroelectric Project Tree House Archaeological Project
Summary
From 2008 through 2010, SCE&G conducted archaeological data recovery investigations at the Tree House Site (38LX531) located along the Saluda River in Lexington County, South Carolina.
The Tree House Site is a large, well preserved, deeply stratified archaeological site with prehistoric occupations ranging from approximately 13,500 to 700 years ago. Data recovery investigations included the excavation of approximately 200 square meters up to 3.65 meters deep, making it one of the largest, most logistically challenging archaeological projects ever undertaken in South Carolina. More than 37,000 artifacts were recovered and 80 pits, hearths, and posts were excavated. Also uncovered were the remains of one Middle Woodland Period structure (ca. 2,500 to 1,500 years old), and possible Early and Middle Archaic structures (ca. 10,000 to 5,500 years old). The latter two structures are among the oldest known structures ever found in South Carolina.
Background
The Tree House Site (38LX531) is located along the lower Saluda River, approximately one mile downstream from the Lake Murray dam. The site was initially discovered in April 2006 during a Phase I survey being conducted as part of SCE&G’s Application for New License for the Saluda Hydroelectric Project. Based on initial Phase I and subsequent Phase II investigations, the site appeared to contain archaeological deposits spanning more than 10,000 years. An agreement was reached between SCE&G, FERC, the South Carolina State Historic Preservation Office (SHPO), and the Catawba Indian Nation Tribal Historic Preservation Office (THPO), and Phase III data recovery investigations were undertaken to mitigate the adverse effects of erosion occurring on the portion of the site located on private property.
Challenge
In consultation with the SHPO and THPO, a data recovery plan was developed that specified various research questions that would be addressed during the investigations. One of the primary research issues was examining diachronic change from the Paleoindian through Mississippian Periods (13,500 to 500 years ago). Unlike other parts of the eastern United States, the sequence of cultural phases is not well established in the vicinity of the study area.
Innovation
To address the new investigative challenges of the site, an excavation strategy was devised and implemented.
One of the major challenges of the investigation was to obtain as much information as possible using good archaeological excavation methods and recording procedures, while at the same time ensuring the safety of the archaeologists by complying with OSHA excavation safety requirements. Typically, archaeological excavation blocks are excavated with vertical walls to maximize surface exposure to gain a better understanding of the site’s stratigraphy and to also ensure standardized sampling of the soils and artifacts. Because archaeological deposits at the site were more than 3.5 meters deep, and soils were classified as unconsolidated loamy sands (Type C soils), an innovative approach to excavation was necessary.
To ensure the safety of the workers, excavation blocks were benched and sloped using a design approved by a licensed Professional Engineer with more than 20 years of experience in geotechnical explorations. Each block had a combination of hand excavation and mechanical excavation. A staff member performed daily inspections at the site to ensure that OSHA trenching and excavation safety guidelines were being adhered to, and a professional engineer and safety coordinator conducted periodic safety inspections.
Results
As a result of the excavation, more than 37,000 artifacts were recovered and 80 pits, hearths, and posts were excavated.
The excavations and resulting report not only fulfilled SCE&G’s requirements under Section 106 of the National Historic Preservation Act, but also satisfied the concerns of the FERC, SHPO, THPO, and other stakeholders, who were extremely pleased with the results of the investigations.
In addition, SCE&G is currently preparing artifact and interpretive displays at two local public facilities, Saluda Shoals Park and the Lake Murray Visitors Center. Combined, these facilities attract more than 400,000 visitors each year, including many school groups. SCE&G is also producing an educational booklet describing the general history and prehistory of the area, as well as the results of the excavations at the Tree House site. This brochure will be provided to the public at no cost. Lastly, SCE&G will protect and preserve their portion of the site in perpetuity through a restrictive covenant. Not only does this ensure preservation of the site for future generations, but it is extremely cost-effective in that time-consuming and expensive excavations did not have to be conducted on that portion of the property.
Stakeholder Quotes
“It is our opinion that they [SEC&G] went above and beyond the call of their legal responsibilities of Section 106 of the national Historic preservation Act in covering the costs for obtaining this extremely important data from the site.” –Wenonah G. Haire, DMD, Tribal Historic Preservation Officer, Catawba Indian Nation
