[1][4] B. subocularis has a row of small scales (suboculars) between the lower border of the eye and the upper labials.

[5] Coloration is yellow to tan dorsally with a series of black, or dark brown, H-shaped markings.

[6] The Trans-Pecos rat snake's habitat consists of desert flats and brushy slopes, and rocky outcrops where it dens.

[citation needed] A nocturnal species, B. subocularis is uncommon and rarely seen in the wild, save on warm summer nights during the breeding season.

[2][3] The breeding season for B. subocularis runs through May and June, while egg-laying begins in July and ends by September.