“I reached some plains so vast, that I did not find their limit anywhere I went, although I travelled over them for more than 300 leagues … with no more land marks than if we had been swallowed up by the sea …. [T]here was not a stone, nor bit of rising ground, nor a tree, nor a shrub, nor anything to go by.”

Francisco Vasquez de Coronado in a letter to the King of Spain on Oct. 20, 1541, describing the Llano Estacado, somewhere on the southern great plains (i.e. the Panhandle) of Texas