The Possum Hollow site is a good example of what archeologists call an "open terrace site. " The archeological record indicates that Possum Hollow was repeatedly occupied by prehistoric people over thousands of years, probably in brief camping episodes, with each episode lasting a couple of days or weeks. Concurrent with periodic use of the site through time, the river would flood and deposit thin layers of sediment over debris left by the campers. The terrace gradually built up as time went by—six to eight feet of sediment built up over several thousand years—sandwiching stone tools, animal bones, mussel shells, charcoal, and hearth features in the layers. Radiocarbon assays suggest the site was used from 1300 B. C. to 1550 A. D.