BOB Hydrographics, LLC (BOB) conducted a marine archaeological assessment in support of the Orange County South Terminal Project. The South Terminal is proposed on an oxbow channel of the Neches River, downstream from Beaumont, to accommodate loading and unloading of ships and barges and an adjacent tank storage facility. Plans for marine portions of the property include construction of two ship docks and one new barge dock. Dredging will remove sediments down to an elevation of -42 feet (ft) Mean Lower Low Water (MLLW) to create ship berths and a turning basin. Planned future expansion would increase the depth of the berths and turning basin to -48 ft MLLW. A barge dock will be dredged along the edge of the Neches River Channel to an elevation of -17 ft MLLW. Pilings will be driven to support dock and gangway platforms and to create mooring and breasting dolphins and barge monopiles. A portion of the oxbow, west of the ship docks will be filled to create upland as part of a proposed storage tank facility. Horizon Environmental Services, Inc. contracted with BOB, on behalf of the project sponsor, Port of Beaumont Navigation District, to assess the potential for submerged archaeological sites within the proposed South Terminal. Submerged archaeological sites, in this context, might be historic sites, such as sunken or abandoned watercraft, which may be eligible for the National Register of Historic Places or as State Antiquities Landmarks. The South Terminal will be constructed on publicly owned land; therefore, Texas Antiquities Permit 8926 was obtained prior to beginning fieldwork. A review of the cultural background determined that 3 prior marine archaeological investigations have been conducted within 3 miles of this project. At least 7 wrecks have been reported within 3 miles of the survey area. Field investigations included marine geophysical survey and probing of 2 anomalies. Geophysical survey was completed by BOB from June 10-13, 2019. A total of 78 acres was surveyed. The submerged Area of Potential Effect totals 54.7 acres, including: 34.3 acres for dredging ship and barge berths, 10.3 acres for ship docks and storage tanks, and 10.1 acres of survey buffer, mandated by the Texas Historical Commission, along the eastern margin of the dredging footprint. The Principal Investigator was solely responsible for archaeological data analysis and report preparation. Preliminary analysis of geophysical survey data resulted in recommendations of archaeological avoidance for 3 potential historic sites, designated as Anomalies 1, 2 and 3. Additional investigation was conducted from August 26-29, 2019 and January 19-21, 2020. Probing disproved the significance of Anomaly 1. Closeorder magnetometer survey disproved the significance of Anomaly 2. Probing determined that Anomaly 3 is associated with a buried, wooden-hulled watercraft, Site 41OR113, measuring 32 feet wide and at least 82 ft long. Site 41OR113 is potentially eligible as a State Antiquities Landmark and for listing in the National Register of Historic Places. All disturbance of the river bottom, related to construction of the South Terminal, must be avoided within state-mandated target avoidance buffers extending 50 meters beyond the margins Site 41OR113. If the wreck cannot be successfully avoided, then further investigation would be required to determine whether the site is historically significant and eligible for the National Register of Historic Places. All portions of the survey area, outside of the 41OR113 avoidance zone, are recommended for archaeological clearance. This study was completed in compliance with Section 106 of the National Historic Preservation Act of 1966, as amended (Public Law 89-665; 16 U.S.C. 470), requiring that the lead agency consider the effects of projects upon historic resources, if those projects receive either permits or funding from the federal government. This study complies with the Antiquities Code of Texas (Texas Natural Resource Code, Title 9, Chapter 191), which provides for the protection of cultural resources on state lands. Title 13, Part 2, Chapters 26 and 28 of The Texas Administrative Code mandates the minimum reporting and survey requirements, respectively, for marine archaeological studies conducted under Texas Antiquities Permits. Archaeological project records are curated at the Center for Archeological Studies at Texas State University in San Marcos. No artifacts were collected during these investigations.