The Page–Ladson archaeological and paleontological site (8JE591) is a deep sinkhole in the bed of the karstic Aucilla River (between Jefferson and Taylor counties in the Big Bend region of Florida) that has stratified deposits of late Pleistocene and early Holocene animal bones and human artifacts. The site was the first pre-Clovis site discovered in southeastern North America; radiocarbon evidence suggest that the site date from 14,200 to 14,550 BP. These dates are roughly 1,000 to 1,500 years before the advent of the Clovis culture. Early dates for Page–Ladson challenge theories that humans quickly decimated large game populations in the area once they arrived. Prehistoric environment At the height of the last ice age (the Wisconsin glaciation), the sea level was up to 100 meters lower than at present. Much more land was above the water along the coast, which was extended much farther to the west. Most of Florida is a thick limestone platform, with typical Karst topography. As limestone is porous, salt water penetrates the lower part of the Florida platform, and fresh water floats on top of the salt water. With the lowered sea level of the ice age, the fresh water table in Florida also was lowered, leaving most of Florida much drier than it is at present. The only reliable sources of fresh water at elevations that are currently above sea level were sinkholes and the deeper parts of river beds. The Page–Ladson site was one of those watering holes, located in a ravine that is now the bed of the river. Before it was inundated by the Aucilla river, Page–Ladson was a sinkhole containing a small pond within it. Currently, Page–Ladson is about 60 m by 45 m wide and 10 m deep. The lower part of the Aucilla River (from the Cody Scarp to the Gulf of Mexico) crosses the Woodville Karst Plain, which consists of a thin layer of sand over limestone bedrock. Much of the flow of the Aucilla River has been captured by an underground drainage system created by karst processes. Sections of the river are entirely underground, surfacing for short stretches and then disappearing again. The Page-Ladson site is located in one of the above ground sections, known as Half-Mile Run (although it is closer to one mile long). Other sites on the Aucilla River also are yielding paleontological and archaeological finds, first as part of the long-running Aucilla