We found the cactus on a south facing slope beside Nottingham Road adjacent to a farm. The presence of spines and three or four areoles per diagonal row at the middle of the cladodes suggests that they are Opuntia mesacantha ssp. mesacantha. The clump was about 20 feet by 20 feet and seemed out of place. The plants looked like someone was weeding them and probably planted.
A trip in the spring when they are in bloom is planned.