Latitude / Longitude:
3,074 ft (937 m)
Central (CST) (UTC-6)
Mount Blanco is a small white hill — an erosional remnant — located on the eastern border of the Llano Estacado within Blanco Canyon in Crosby County, Texas. It is the type locality of the Blanco Formation and Blancan Fauna, which occurs throughout North America.
The term “Blanco Canyon beds”, later shortened to “Blanco beds”, was first applied to this formation in 1890 by William F. Cummins of the Geological Survey of Texas. The Blanco beds are considered to be of lacustrine origin – deposited in a Pleistocene lake basin set in the Ogallala formation of Pliocene age which underlies the upper surface sediments of the Llano Estacado. The thickness of the Blanco beds varies from around 22 to 26 m (72 to 85 ft) thick at the most. The formation mainly consists of light-gray fine-grained mudstone, sandstone, and some conglomerate. These light-colored sediments contrast sharply with the rust-colored sediments of the Ogallala Formation.