Underwater archaeologists, led by James Adovasio and Andy Hemmings of Mercyhurst College, dove at four sites that were first visited in 2009. At these locations, electronically documented intact river channel features of the Pleistocene Suwannee River are now filled with multiple layers of sediment. These sites are covered by 40 to 130 feet of ocean water and are located 50 to 125 miles offshore of the modern Gulf Coast of Florida northwest of Tampa or southeast of Tallahassee. The three shallower sites have bedrock exposed on the seafloor that forms one side of the buried channel. The bedrock at each of these sites is low grade knappable toolstone that could have been used for tool making. The deepest site, Thor’s Elbow, is the intersection of the ancient Suwannee and another river where they expected to find more knappable bedrock buried under the modern surface. At each of these sites divers hoped to locate prehistoric human made artifacts, bones of Pleistocene animals, such as the mastodon, and perhaps datable organic material such as pieces of wood. Any such finds would indicate that the now inundated Pleistocene landscape of Florida in the Gulf of Mexico is still preserved, accessible to archaeologists, and contains prehistoric evidence of the use of this landscape by people and animals alive at the end of the last Ice Age.