Page–Ladson is an underwater archaeological and paleontological site in the Aucilla River sinkhole system of Florida’s Big Bend, preserving late Pleistocene and early Holocene animal bones and human artifacts around what was once a freshwater watering hole. Excavations from 1983 to 1997, later confirmed by work from 2012 to 2014, found stone tools, cut-marked mastodon remains, and evidence of mastodon butchering dating to about 14,200 to 14,550 years before present. These discoveries established it as the first pre-Clovis site identified in the southeastern United States and, at the time, the oldest known site east of the Mississippi, reshaping understanding of early people in Florida and the Americas.