Geologic formations are a striking feature of the Washita Battlefield landscape. While not technically part of the park, the red shale buttes lining the northern horizon are an integral part of the overall cultural landscape. They define the battle site for many.
Another striking geologic feature is found within the park itself. These are outcrops of gypsum, or alabaster, which protrude from the ridge that divides the southern floodplain from the adjoining uplands. Generally pink to white in color, the gypsum stands out from the surrounding soil, and is a distinctive feature of this part of Oklahoma.
