The following checklist contains 36 species that are known to occur and unless otherwise noted have been collected in the county by the author. There are an additional 8 species that are known to occur in adjacent counties and that could be expected to possibly occur in Medina County. One species occuring in Medina County is protected under current state law.
South Texas Blind Snake, Leptotyphlops dulcis rubellum
Diamondback Water Snake, Nerodia rhombifer rhombifer
Blotched Water Snake, Nerodia erythrogaster transversa *
Checkered Garter Snake, Thamnophis marcianus marcianus
Eastern Blackneck Garter Snake, Thamnophis cyrtopsis ocellatus
Redstripe Ribbon Snake, Thamnophis proximus rubrilineatus
Texas Brown Snake, Storeria dekayi texana
Eastern Hognose Snake, Heterodon platirhinos
Rough Green Snake, Opheodrys aestivus
Western Coachwhip, Masticophis flagellum testaceus
Schott's Whipsnake, Masticophis schotti schotti
Central Texas Whipsnake, Masticophis taeniatus girardi
Yellowbelly Racer, Coluber constrictor flaviventris *
Texas Indigo Snake, Drymarchon melanurus erebennus * (Protected Species)
Texas Patchnose Snake, Salvadora grahamiae lineata
Texas Glossy Snake, Arizona elegans arenicola *
Bull Snake, Pituophis catenifer sayi
Western Snake, Pantherophis obsoletus
Northern Plains Rat Snake, Pantherophis emoryi emoryi x meahllmorum
Baird's Rat Snake, Pantherophis bairdi
Mexican Milk Snake, Lampropeltis triangulum annulata *
Desert Kingsnake, Lampropeltis getula splendida
Prairie Ringneck Snake, Diadophis punctatus arnyi
Ground Snake, Sonora semiannulata semiannulata x taylori
Rough Earth Snake, Virginia striatula
Texas Longnose Snake, Rhinocheilus lecontei tessellatus
Flathead Snake, Tantilla gracilis
Plains Blackhead Snake, Tantilla nigriceps
Southwestern Blackhead Snake, Tantilla hobartsmithi
Texas Night Snake, Hypsiglena torquata jani *
Texas Coral Snake, Micrurus tener tener * *
Broad-banded Copperhead, Agkistrodon contortrix laticinctus * *
Western Cottonmouth, Agkistrodon piscivorus leucstoma * *
Western Diamondback Rattlesnake, Crotalus atrox * *
Northern Black-tailed Rattlesnake, Crotalus molossus molossus * *
Mottled Rock Rattlesnake, Crotalus lepidus lepidus * *
Brown, Bryce C. 1950. An Annotated Check List of the Reptiles and Amphibians of Texas. Baylor University Press, Waco.
Conant, R. 1975. A Field Guide to Reptiles and Amphibians of Eastern and Central North America, 2nd edition. Houghton Mifflin, Co., Boston.
Dixon, James R. 2000. Amphibians and Reptiles of Texas, 2nd edition. Texas A & M Press, College Station.
Werler, John E., and James R. Dixon. 2000. Texas Snakes, Identification, Distribution and Natural History. University of Texas Press, Austin.