So, you’re wondering about venomous snakes in Kentucky? If that’s the case then we can only guess that you’re considering hopping over to the Bluegrass State to explore the lakes, the mountains, the rivers, and the fried chicken-scented streets. Great choice! This is one darn stunning corner of the USA.
But you’re right to do a little research into what serpents await once you arrive. The reason? This whisky-doused place of banjo pickers is also home to some of the most feared sliders in the country. Some can kill, others can do a whole load of damage.
That’s where this guide comes in. It’s a complete look at all the venomous snakes in Kentucky, along with one bonus snake that we think you should be wary of, if only because it likes to hang with venomous snakes! Of course, our selection is heavy on the rattlers, which are by far the most formidable customers in this land south of the Mason–Dixon line.
Cottonmouth (Agkistrodon piscivorus)

Of all the venomous snakes in Kentucky, the cottonmouth is the best swimmer. In fact, they are one of the few truly semi-aquatic vipers anywhere on the globe, just at home in the H2O as they are in the woods and rocky outcrops of the Bluegrass State. They aren’t found all over the territory, though – Agkistrodon piscivorus, the subspecies native to Kentucky, are actually limited to the extreme western regions close to the border with Missouri.
Relatively large as rattlers go, this one can hit lengths of over 80cm, and the ladies are usually a touch smaller than that. They have a blunted nose and a body that gets fatter in the middle before tapering off to a pointed tail. At a young age, the coloring of a cottonmouth is often bolder and brighter shades of brown and tan. Adults can turn hues of olive green and grey, but usually showcase several rings of black along the torso.
Cottonmouths tend to be quite aggressive customers. Research shows that nearly 80% will prefer to confront danger with a display of force than to slink away. That’s not great news for those who happen upon them on the trail, because they can back up their posturing with a gnarly cytotoxic venom that’s been known to lead to amputation on account of its necrotic capabilities. Deaths do remain rare, however, with most estimations saying that they’re responsible for something like one fatality per year in the stars and stripes.
Copperhead (Agkistrodon contortrix)

Also known as the Eastern copperhead because it mainly lives in the eastern portion of the United States, this snake is a very common find in Kentucky and a whole range of other Dixie states besides, from Kansas all the way to Louisiana. They are named and known for their rusty coloring, which runs the whole body in a sort of orangey-red hue, only occasionally interrupted by an hourglass marking of darker brown and black.
During the cooler months, the copperhead will retreat to holes cut into the rock to hibernate, sometimes in the company of other venomous snakes and even rat snakes (more on those later). When it’s warmer, they’re happy in a number of other environments, particularly thicky covered forest ground and mixed woodland, which makes the Bluegrass State something of a favorite.
Bites from copperheads can be fatal but rarely are. The venom here is nowhere near as deadly as that of timber rattlesnakes and is even weaker than that of the cottonmouth. On top of that, this species is known for going for dry bites before actually committing to an attack. That means you can be bitten but get little to no envenomation. Still, we’d recommend keeping your distance, especially if they enter attack mode and start vibrating those tails!
Timber rattlesnake (Crotalus horridus)

The home of bluegrass pickers and fried chicken is actually the epicenter of the range of the much-feared timber rattlesnake. Yep, these venomous serpents exist in all four corners of the state, from the lowland hills at the end of Appalachia in the east all the way to the Land Between the Lakes out west. They can get used to a range of different habitats, but usually stick to heavily forested valleys with water sources, or open rock ridges – Kentucky sounds just about perfect, eh?
Timber rattlesnake are officially the largest of all the venomous snakes in Kentucky. They can hit 1.5m per individual with ease, and sometimes even more than that, especially the males. The trademark patterning here is linear, with chevron-style lines running the body in V shapes. There’s also a distinct V shape marking on the top of the head, running alongside or even below the protruding eyes.
Venom wise, it’s not good news. These beefy vipers often inject more per bite than most of their compadres and have one of the more powerful venoms on the continent. We’re talking a potent mix of chemicals known as canebrake toxin that can shutdown whole sectors of the nervous system in just a matter of hours – it’s hardly a surprise that these were the poster boy for American anger in the face of colonialism during the American Revolution!
Pygmy rattlesnake (Sistrurus miliarius)

There’s just a tiny cut-out of the Bluegrass State where it’s possible to encounter the pygmy rattlesnake these days. It sits along the southwestern border with Tennessee, roughly coinciding with the Land Between the Lakes National Recreation Area and the areas to the east and west of Lake Barkley and Lake Kentucky. In fact, there are so few remaining in this part of the US that they are now officially listed by a Species of Greatest Conservation Need by state authorities.
Just as the name implies, these guys are a mini version of the rattlers that you find elsewhere in the USA. They rarely grow to any more than 60cm from end to end and there’s little difference between the adult size of the females and males of the species. You’ll notice them for their bright and bold patterns, which include alternating blotches and spots strung along an often-bright central line of orange or yellow.
The venom these guys posses is also in line with their smaller size – AKA it’s not as deadly as that found in other venomous snakes in Kentucky. It’s still no walk in the park, though, what with a mix of chemicals that can disrupt the neurological system and lead to blood hemorrhaging. Little is known about the behavioral traits of pygmy rattlers because each individual reacts differently; some calm, some aggressive. They are often spotted by humans crossing roads and sunning themselves on the more open sections of hiking trails.
Western rat snake (Pantherophis obsoletus)

Okay, okay, so the keen herpetologists out there will already have noticed that the fifth and final critter on this list of venomous snakes in Kentucky isn’t actually venomous at all. However, we think it should be listed here because it can pose a potential threat to humans, though not because of its bite. In this case, it’s all about size…
These reign as one of the largest snakes in the whole of North America and is actually the single largest snake present in Canada today. We’re talking in excess of 2.5 meters when fully grown in some cases. That’s far longer than your average human height from head to toe! Because they are so large and because they are so popular with snake collectors, physical injuries as a result of a feeding mishap can occur and often require low-level medical treatment. Still, you won’t have to worry about these in the same way as you do the aforementioned rattlers.
Rat snakes are quite easy to discern from their venomous brothers. First off, as we’ve already noted, they are pretty huge – at least twice what most rattlesnakes measure. Second, they have strong patterns of brown and black blotches that run the whole length of the body. Oddly, these snakes will often be found hibernating alongside cottonmouths and other venomous snakes during the colder months.
Venomous snakes in Kentucky – our conclusion
There are just four proper venomous snakes in Kentucky. They include the cottonmouth, which is a master of swimming, and the copperhead, its close cousin that likes to live in the state’s wooded and rocky areas. You should also pay special attention to the feared timber rattlesnake. That’s probably the most venomous snake in Kentucky – it has the power to kill a human by shutting down key parts of the nervous system, though deaths do remain rare. Finally, there’s the pygmy rattler, a small and uncommon snake in Kentucky that you’ll only encounter in the far western portions of the state.