Mount Blanco, a small white hill in Blanco Canyon on the eastern edge of the Llano Estacado in West Texas, is a major North American fossil site and the type locality of the early Pleistocene Blanco Formation and Blancan fauna. Named in 1890 by William F. Cummins, the pale beds here were laid down in a shallow, seasonal pond basin over the older Ogallala Formation. Their volcanic ash helps date them to a critical interval near the beginning of the Pleistocene. Fossils from this semi-arid grassland environment include horses, camels, peccaries, deer, canids, cats, sloths, gomphotheres, and glyptodonts, making the site central to North American paleontology.