Which preposition to use with estacado

of Occurrences 1%

The man was the veteran cowboy, Budd Hankinson, who had whirled the lasso on the arid plains of Arizona, the Llano Estacado of Texas and among the mountain ranges of Montana; who had fought Apaches in the southwest, Comanches in the south and Sioux in the north, and had undergone hardships, sufferings, wounds and privations before which many a younger man than he had succumbed.

Which preposition to use with  estacado