Predictive Modeling and Preliminary Archeological Resources Assessment of the Northern Arc Alternatives

In coordination with the Georgia Department of Transportation and the Georgia Historic Preservation Division, R.S. Webb & Associates developed an archeological survey plan to reliably, yet efficiently, identify potentially significant archeological resources in the study corridor. The survey plan was comprised of three main efforts:

1) Predictive modeling of locations with a high probability of containing

archeological sites;

2) Archeological field reconnaissance survey to test and complement the predictive

model; and

3) Responsive field surveys to locate, validate and assess archeological sites reported

through other efforts such as public comment.

The above efforts were conducted during the period of July through November 2001 and focused specifically on the proposed Northern Arc between U.S. Highway 41 and Georgia Highway 400. This section of the proposed Arc traverses Forsyth, Cherokee and Bartow Counties, Georgia and consists of alternative corridors totaling about 117 kilometers (73 miles). Once selected, the final route will be approximately 80 kilometers (50 miles) long, 305 meters (1,000 feet) wide.

The predictive model was developed by Brockington and Associates and was used to estimate locations within the overall study corridor where prehistoric archeological resources are likely or unlikely to occur, and identify areas where archeological sites are likely to occur but have not been recorded. The model was tested against a sample of 1,966 known archeological sites. The model accurately encompassed 89 percent of the sample within areas viewed by the model as likely to contain prehistoric archeological resources. The predictive model was then used to rank the various Northern Arc alternative routes by percent surface area likely to contain archeological resources.

The archeological reconnaissance was conducted by R.S. Webb & Associates and was designed to be corroborative, intuitive and responsive. Corroborative field surveys were conducted on locations where known, potentially significant and previously recorded archeological sites were believed to be located. The goal of these efforts was to confirm the presence or absence of recorded sites that have an unknown, potentially eligible or eligible National Register of Historic Places (NRHP) eligibility status.

Intuitive field surveys were conducted on arable alluvial and up! and settings adjacent to major stream crossings that were considered to have a high probability of containing archeological sites, but where no known sites were previously recorded. The goal of these surveys was to determine if unrecorded archeological resources were present at these locations, and to make general assessments about the NRHP eligibility status of detected archeological resources (i.e., ineligible, potentially eligible, eligible). The logic behind this approach was to identify major archeological resources such as large prehistoric habitation sites or historic Indian farmsteads as early as possible so that such sites could be avoided, or the adverse effects to them minimized.

The locations of ten previously recorded sites were visited during the corroborative field survey. Four of these sites could not be relocated, and are believed to be at some other location. Two sites were found to be severely disturbed and were considered ineligible for the NRHP. Three sites are located within the study corridor and considered potentially eligible for the NRHP. The remaining site was previously excavated as a result of the construction of Interstate 575.

A total of 67 locations within the study corridor were investigated during the intuitive and responsive surveys, resulting in the detection of 17 new archeological sites, three rock shelters, five isolated artifact finds and one cemetery. Of the archeological sites, eight are considered potentially eligible for the NRHP. The three rock shelters have an unknown eligibility status because prehistoric occupation could not be confirmed. The cemetery dates to the 19th century and is considered potentially eligible for the NRHP. In addition the cemetery is protected under state law.