What specific color variant is recognized in southern Louisiana and Texas areas of the range?

Texas rat snake variant showing orange or red pigmentation between scales

Coloration in the Western Rat Snake can vary geographically, often leading to distinct regional classifications or common names. In the southern extent of the range, specifically encompassing southern Oklahoma, Texas, and Louisiana, a recognized color phase exists known as the Texas rat snake variant. This variant is characterized by an individual having a brown-to-black overall body color, but notably displays visible orange or red pigmentation emanating from the skin present between the scales. In southern Louisiana specifically, this characteristic scaling can give the snake a pronounced calico appearance, distinguishing it from the generally darker or faintly blotched adults found further north in the distribution.