Calcasieu Lake records a Holocene history of dramatic environmental change. The changes resulted in up to 20–30 km of landward translation of deltaic and estuarine depositional environments, and intervening periods of delta progradation, from 9600 cal B.P. to 1600 cal yr B.P. The sediments preserved beneath the lake record a series of back-stepping events. Seven events that affected the entire estuary are recognized: at 8900–8500 cal yr B.P., 8300–8000 cal yr B.P., 8000–7900 cal yr B.P., 7200 cal yr B.P., 5800–5600 cal yr B.P., 2000–2800 cal yr B.P., and 2500–1800 cal yr B.P. Only one of these events (8200 cal...