GSPag` said:
12f,
I would believe there are no Cottonmouths up on the Plains. But they do exist off the Caprock. I looked at the map, and it does need to be expanded. I saw many Cottonmouths on Lake Greenbelt and on some of the larger lakes on ranches in that area. I had cowboys tell me that if a snake floats across the water, then dont't take your horse across.
Well they have never been recorded in the panhandle or anywhere near Lake Greenbelt, as far as I can tell. That area isn't under collected either. Even the late, great aggie Dr. Jim Dixon didn't have any records close to there in his comprehensive dot locality map in his book Texas Snakes (aka the Texas Snake Bible). Cottonmouths are well studied, well collected, and easily found were present. There are none from the panhandle.
Inaturalist (the link I provided) is pretty good, especially in Texas, of recording common species throughout their range. No records.
The reality is western Texas and northwestern Texas just does not provide adequate habitat for cottonmouths. It's a riparian/watershed thing. They are an eastern adapted species that has persisted west in certain riparian areas.
My great uncle was THE cowboy, Super knowledgeable about the south central Texas coast and ranch manager of one of the major old money Texas ranches. I remember quail hunting with him in the early 90s and him yelling at us not to shoot a broken covey because it was prairie chickens (legit). I don't think he knew **** about snakes and everything wet was a cottonmouth.
