Revised Addendum (3rd) Phase I Archaeological Resources Survey and Assessment of Effects of the Proposed Reconstruction of the I-16/I-75 Interchange, Bibb County, Georgia

In December of 2019 and January of 2020, VHB conducted an addendum Phase I Archaeological Resource Survey of the proposed reconstruction of the interchange between I-16 and I-75 in Bibb County, Georgia.

The I-16/I-75 interchange reconstruction is being undertaken by the Georgia Department of Transportation (GDOT) and is comprised of project PI Nos. 311000, 311005, 311400, and 311410. The overall reconstruction project also includes PI Nos. 0012699, 0012700, and 0012701 which have been separately designed to assist in implementing the project through construction phases. As an addendum, the current survey investigated four portions of the project APE that extended beyond the limits of previous archaeological survey. These four areas are known as Addendum APE 1 – 4. The purpose of the current survey was to record new archaeological resources and revisit all known resources located within the Addendum APE (1-4) and then evaluate those resources through the application of the NRHP criteria.

Prior to fieldwork, two archaeological sites and two historic districts were located within the limits of Addendum APE 1, and 1 historic district was located within the limits of Addendum APE 3. Addendum APE 1 is located within boundaries of the NRHP-listed Ocmulgee National Monument Historic District (ONM) and within the larger boundaries of the NRHP-eligible Ocmulgee Old Fields Traditional Cultural Property (TCP). Also, within Addendum APE 1 are two previously recorded archaeological resources: Site 9BI1 (a contributing element to the ONM’s NRHP listing under Criterion D) and the Ocmulgee Bottoms site (OCMU-8) which was previously identified within the floodplain south of the Macon Plateau by National Park Service (NPS). Additionally, a portion of Addendum APE 3 was located within the NRHP-listed boundary of the Macon Historic District.

Since Addendum APE 4 had been the subject of previous archaeological survey, this area was considered sufficiently covered for archaeological resources and no additional fieldwork was conducted. Fieldwork within Addendum APE 2 and 3 consisted of systematic shovel testing at 30 m intervals along transects within the survey area. Through coordination with GDOT OES, methodologies were developed to revisit the previously recorded archaeological sites within Addendum APE 1 and included 15-m shovel testing and 30-m shovel test augering along transects within previously recorded archaeological site boundaries.

As a result of the survey 480 shovel tests were excavated within the limits of Addendum APE 1, 2, and 3. No above ground features associated with any archaeological site were identified within any addendum survey area. Furthermore, shovel testing within the limits of Addendum APE 2 and 3 were negative for archaeological material.

Phase I survey within Addendum APE 1 identified cultural material in 51 shovel tests which resulted in one IF and the revisit to 9BI1 and the Ocmulgee Bottoms site. Positive shovel tests were encountered across the site boundaries of both 9BI1 and the Ocmulgee Bottoms, and as a result of the addendum survey, the boundaries of 9BI1 have been expanded to encompass the entirety of the Ocmulgee Bottoms site, now considered a floodplain locus of 9BI1. While 9BI1 is recorded in the Georgia Archaeological Site Files as one site including both the Macon Plateau and the Ocmulgee Bottoms, the NPS Ocmulgee Mounds National Historical Park considers them separate sites for park management purposes. In addition, the site boundary of 9BI1 has been expanded to include additional deposits and new areas of the site identified within Addendum APE 1. The portion of Site 9BI1, located within Addendum APE 1, is PI Nos. 311000, 311005, 311400, and 311410 – Revised Addendum (3rd) Phase I Archaeological Resources Survey Management Summary ii. a moderately dense artifact scatter of precontact and historic material located to the north and south of the I-16 roadway and within the newly established Ocmulgee Bottoms Locus.

Within Addendum APE 1, some areas of 9BI1 retain good integrity and have significant data potential at depths between the ground surface and 1 meter. These areas were identified north of the I-16 corridor from about 900 meters southeast of the Norfolk Southern Railroad bridge to the southeastern terminus of the APE. These identified deposits within the survey area retain integrity of location, materials, design, and association and contain significant data potential related to the human occupation and cultural development of the floodplain during the Middle to Late Mississippian Periods. Since previous archaeological excavations have shown additional intact and significant archaeological deposits at 9BI1 to depths in excess of what could be studied in the current survey, the site is also considered to contain significant data potential under Criterion D related to the human occupation and cultural development of the floodplain from at least the Early Archaic period through the nineteenth century.

The addendum survey area in the location of Addendum APE 1 overlaps portions of the ONM and the larger Ocmulgee Old Fields TCP cultural properties. As the identified deposits within the newly expanded areas of 9BI1 are located within these larger resources, and are considered significant, the deposits contribute to NRHP listing and eligibility of these cultural properties. The significant and contributing deposits of 9BI1 are considered Environmentally Sensitive Areas (ESAs) and have been labeled and marked on current design plans. Orange Barrier Fencing (OBF) will demarcate these areas of significant and contributing deposits. In other areas of the site within the addendum survey area, a vertical ESA has been established which will prevent soil disturbance below 1 m (~3 ft) north of the I-16 corridor, and below 2.7 m (~9 ft) south of I-16. The project as currently designed will avoid the ESAs and is anticipated to have no adverse effects to the significant and contributing deposits within the newly expanded site boundaries of 9BI1.