Waco Mammoth National Monument in Waco, Texas, preserves one of the United States' most important Ice Age fossil localities, including the remains of 24 Columbian mammoths and other Pleistocene animals. It is especially significant as the largest known concentration of mammoths believed to have died in repeated flooding events in the same area. Evidence indicates a nursery herd perished about 68,000 years ago, with later floods claiming additional animals over time, without human involvement. Discovered in 1978 near the Bosque River, the site was excavated for years and now protects fossils still in place, serving both scientific research and public interpretation.