Fossils from land, seashore, and open sea have all been found here. Human footprints are found above, with, and below prints of bears, saber-toothed tigers, mammoths, and dinosaurs. Lamination markings, indicating that the foot pressed through different colored clays beneath it, are also to be seen on many of the human and animal tracks. Over a hundred human footprint trails have been studied in the Paluxy River area. Most of the footprints are unshod, but some appear to have some kind of covering on the foot.
Some marks are of children's feet, but always going somewhere with adults.
Some are of giants. Each one will have length of strides to match the footprint size. An anthropological rule of thumb holds that the length of the foot represents about 15 percent of an individual's height. C.N. Dougherty, a local chiropractor in the Glen Rose area, wrote a book, Valley of the Giants, in 1967. He has located, described, and photographed many of the human prints.