🇺🇸 United States · Earthwork
Watson Brake
Middle–Late Archaic (3500–2800 BCE) · Middle Archaic Watson Brake culture
Oldest North American mound complex: 11 mounds 5400 BP enclosing oval plaza, hunter-gatherer monument without agriculture.
🇺🇸 United States · Earthwork
Foster Mounds
Coles Creek 700–1200 CE to Plaquemine 1200–1500 CE · Coles Creek–Plaquemine (Troyville to Mississippian transition Louisiana)
Five-mound complex on Little River near Harrisonburg: largest flat-topped Mound A 8 m high with causeway to plaza, four smaller mounds enclosing 1.5 ha plaza.
🇺🇸 United States · Earthwork
Troyville Earthworks
Woodland Troyville culture 400–700 CE peak (with Baytown 100 BCE–400 CE foundations) · Baytown / Troyville-Coles Creek (Woodland to early Mississippian)
Nine-mound complex at Jonesville where 21st Louisiana's tallest pre-Columbian mound (Great Mound, 82 ft) stood until levee leveling. Baytown-Troyville-Coles Creek sequence with plaza and embankment.
🇺🇸 United States · Earthwork
Poverty Point (Monumental Earthworks of Poverty Point)
Late Archaic 1700–1100 BCE (peak 1500–1200 BCE) · Poverty Point culture
Late Archaic earthwork complex (1700–1100 BCE) with six concentric C-shaped ridges (1.2 km outer diameter) and six mounds, including 22 m-high Mound A – one of largest Archaic earthworks in North…
🇺🇸 United States · Earthwork
Marksville State Historic Site
Marksville 0–400 CE · Marksville culture
Semicircular enclosure 530 m wall, Marksville Southern Hopewell 0–400 CE.