"The 'Staked Plains' tale is deeply entrenched in Texas mythology, but the real interpretation of Llano Estacado is sensible geologic: it means 'stockaded' or 'palisaded' plains - which is precisely how the edge of the plains appear when viewed from below the caprock."[REF] .
The Ogallala formation is a wedge of sediments built up eastward of the Rocky Mountains as they were uplifted in the Miocene, with the consequent alluvial fans referred to as the "Gangplank" [REF].