Q: I acquired a small ranchette on the Blanco River outside of Wimberley at the beginning of the year, and my family and I have been going out there almost every weekend since. It has a great swimming hole that my two boys, age twelve and nine, and their friends have really been enjoying. On the past two trips, however, we’ve come across snakes in the water. I don’t know if they’re water moccasins or a less ominous species, but they’ve rattled (no pun intended) me enough to forbid any swimming. Needless to say, everybody is bummed out. Am I being overly cautious or am I doing the right thing? It’s getting hot and we want to swim.

Janet Williams, Austin

A: Remember the haunting snake scene from the thirty-fifth chapter of Lonesome Dove? If you’ve had the pleasure of reading Larry McMurtry’s epic masterpiece, you surely do, as it paints a picture as unforgettable as it is horrific. The Texanist is operating under the assumption that you have read it, as he assumes that all Texans have, especially a Texas rancher—er, ranchetter—such as yourself. Anyway, you’ll recollect that in that particular chapter, the cowboys from the Hat Creek Cattle Company, led by retired Texas Ranger captains Woodrow F. Call and Augustus “Gus” McCrae, are in the early stages of their big cattle drive from Lonesome Dove, a speck down on the Texas-Mexico border, up to Montana. Then, just as the fellas are crossing the Nueces River in South Texas, the young Irish immigrant Sean O’Brien meets a most dreadful demise after he and his horse are overcome by a large flotilla of wriggling western cottonmouths (the water moccasin’s official name). It’s awful all-the-way-around. Sean’s brother Allen, if you’ll recall, is so torn up about his little brother’s death that he can’t even finish the gloomy Irish song he sings in his honor at the hasty open-range funeral service. Remember that? Man, oh, man, that was sad.

The Texanist brings all of this up not to freak you out more than you are already freaked out, but rather to allay the understandable but mostly baseless fears you are no doubt having about your own boys meeting a similar fate. See, Lonesome Dove is a work of fiction. And this scene, you’ll be happy to hear, is particularly fictitious. Despite the existence of a fair amount of popular lore telling us that cottonmouths occasionally swarm, or school, or ball up into a snaky mass like the one in which poor Sean O’Brien became tangled (in addition to Lonesome Dove, see Willie Morris’s autobiographical North Toward Home, and Jeff Nichols’s McConaissance-era film Mud), the truth is that these particular slithering creatures don’t ever do this. The Texanist even reached out to his herpetologist friends at the Texas Parks and Wildlife Department for confirmation of this, which he got.

Even so, you do have some reason to be concerned. Texas is home to some 115 species and subspecies of snakes, more than any other state in the Union. Among the oodles and oodles of serpentine slitherers are ten venomous species: seven types of rattlers, including two pygmy versions; copperheads; coral snakes; and Western cottonmouths—the only venomous water snakes found in the U.S., so named because of the cottony whiteness of the inside of their mouths, which they will feistily display when threatened.

On the outside, cottonmouths are drab dark brown, olive-brown, olive-green, or almost all black, and are often marked with wide, dark bands, which are more distinct in young snakes. They average about three and half feet in length but have a beefy build and a blocky triangular-shaped head with an obvious neck. Another distinguishing feature of the cottonmouth is its creepy style of swimming, which involves the snake’s body appearing very buoyant as it slides across the water while holding its head fairly high above the surface. Keep an eye out for this unique feature.

Learning to identify a cottonmouth, as opposed to non-venomous and much less-dangerous water snakes, will be key to once again enjoying your swimming hole. Do the snakes you’ve been seeing have triangular heads and brown, olive-brown, olive-green, or almost all black bodies, with wide dark bands? And do they have that distinctive swimming style? If so, then maybe you should continue to exercise caution. But if the snakes don’t meet any of those criteria, the Texanist is of the opinion that with a little training, some keen-eyed vigilance, and the appropriate amount of caution, it would be perfectly reasonable for you to lift your swimming ban. (Take comfort too in the fact that snakes, whatever the species, do not want to be around your kids any more than you or your kids want to be around them. They are there because, like you, they enjoy the place, especially during these hot months, when, like you, they enjoy a refreshing dip. And who could blame them?)

The Texanist feels compelled to point out that while his Parks and Wildlife friends could not—probably for legal reasons—green-light continued swimming, they did not in any way red-light it, either. So, last one in’s a rotten egg! And if you’d like the Texanist to be the first one in, just say the word. Come summertime, there are few things he loves more than a good swimming hole on a scenic stretch of Hill Country river.

Have a question for the Texanist? He’s always available here. Be sure to tell him where you’re from.

A version of this is published in the August 2018 issue.