I had misclassified this lizard as a Clark's Spiny Lizard until I saw some more of these lizards in the same area four years later. After checking various references, I realized that this was the type now classified as Southwestern Fence Lizard. This is a recently-elevated species; formerly it would have been considered a subspecies of the Eastern Fence Lizard.

Here's one of the same lizards that I saw in the same area four years later, but which I recognized instantly as not being a Clark's Spiny Lizard.