The Grand Gulf Mound (22CB522) is an Early Marksville culturearchaeological site located near Port Gibson in Claiborne County, Mississippi, on a bluff 1 mile (1.6 km) east of the Mississippi River, 2 miles (3.2 km) north of the mouth of the Big Black River. The site has an extant burial mound, and may have possibly had two others in the past. The site is believed to have been occupied from 50 to 200 CE. Copper objects, Marksville culture ceramics and a stone platform pipe were found in excavations at the site. The site is believed to be the only site in the Natchez Bluffs region to have been actively involved in the Hopewell Interaction Sphere. It is one of four mounds in the area believed to date to the Early Marksville period, the other three being the Marskville Mound 4 and Crooks Mounds A and B, all located in nearby Louisiana. The mound itself was built in several stages over many years, very similar to the Crooks Mound A in La Salle Parish, Louisiana. Unlike some other Hopewell sites, such as the Tremper Mound in Scioto County, Ohio, the site showed no evidence of a mortuary or communal structure previous to the construction of the mound. The beginning stage is believed to have been a rectangular earthen platform .5 feet (0.15 m) in height, 20 feet (6.1 m) wide on its east–west axis and 3.5 feet (1.1 m) long on its north–south axis. After a period of use, this platform was covered with a mantle of earth 5.5 feet (1.7 m) in height and 26.5 feet (8.1 m) wide along its east–west axis, with an extremely hard cap of earth 0.2 feet (0.061 m) covering the mound. During a third stage another mantle of earth was added to the mound, bringing it to a height of 10 feet (3.0 m) and to approximately 32 feet (9.8 m) in width on its east–west axis.
^ abcBrookes, Samuel O. (1976). The Grand Gulf Mound: Salvage Excavation of an Early Marksville Burial Mound in Claiborne County, Mississippi. Mississippi Archaeological Survey Report. Jackson, Mississippi: Mississippi Department of Archives and History.