I'm calling this Pale Yucca rather than Twist-leaf because of the glaucous leaves which have little or no twist in them*. These two yuccas overlap by several counties in the Lampasas Cut Plains region and I'm not entirely convinced they do not hybridize occasionally.

This example was along the high portion of Oglesby-Neff Park Road in eastern Coryell County, several miles west of the state park.

(* Based on my observations, I'm convinced the two major manuals for us (Manual of Vascular Plants of Texas, and Flora of North-Central Texas) both have the "leaf margin" details of these two species mixed up. I see many/most examples of Twist-leaf Yucca with yellow margins, compared to the several examples of Pale Yucca I've photographed recently which all have dark red leaf margins--exactly the opposite of what the keys would lead you to believe.)