Know Your Venomous North American Snakes

When the weather gets nice, it’s time for the hikers, campers, and outdoor enthusiasts to come out of hiding… which happens to correlate with an uptick in snake activity (including venomous ones).

First things first, I’ll say that I’m not one of those people who believes all snakes should be killed on sight. If a snake is non-venomous, I’ll let it slither on it’s way every time. If it’s venomous, and too close to my house or yard, that’s when a decision has to be made.

In order to make that decision, I first need to identify the species of snake and determine whether or not it’s a venomous snake.

Despite the fact that we only have 4 major species of poisonous snakes to deal with in North America, it can be surprisingly difficult to calmly ID these snakes in the heat of the moment. In fact, that’s why I’m writing this article, to make it easier for the non-snake experts among us to avoid a nasty and potentially fatal bite.

The 4 Big Ones

These are the 4 groups of poisonous snakes that you may run across in the US:

  • Rattlesnakes
  • Cottonmouths
  • Copperheads
  • Coral Snakes

When I say that there are 4 major species of venomous snakes, that’s a bit of an oversimplification, BUT that actually makes the identification process easier.

You see, it doesn’t matter much if you’ve spotted a Texas Coral Snake or an Arizona Coral Snake, both are deadly poisonous. So stay away.


Rattlesnakes, just like Copperheads and Cottonmouths, are part of the pit viper family. Thus they each have similarly large, triangular shaped heads. Aside from their colors and scales, these species have very similar head shapes.

While rattlesnakes have been associated with deadly defiance in American folklore — i.e. the “Don’t Tread on Me” flag — there’s something else to take away from that symbol: Rattlesnakes tend to warn those who come too close (by shaking their rattles).

The US is home to 16 species of rattlesnakes, all are venomous and all of them have the characteristic rattle. When it comes to geographic distribution, the rattlesnake’s habitat is virtually coast-to-coast, with a few exceptions (most notably Hawaii and Alaska). So no matter where you are going in the Lower 48, chances are you’re in rattlesnake country.

Thankfully, these very widespread snakes are also the easiest to identify, thanks to the rattles. The only outliers are juvenile rattlesnakes, which are (as it is in most species) a bit harder to identify, on account of their small, developing rattles and less viperish heads.

Cottonmouth (AKA “water moccasins”)

If you spend a lot of time on the water in the Southeastern US, you definitely want to study up on these sometime aggressive boogers.  True to their name, the inside of their mouth is a pale pink, almost white.

And the reason we know this is because these snakes are known to stand their ground, coiling up and threatening intruders with their open mouths, fangs front and center. Thus, similar to the rattlesnake, their common name was inspired by their natural warning mechanism.

Cottonmouths generally live around the water, in swamps, rivers, and on the edges of lakes. They can often be found sunning themselves on exposed roots and low branches.

The general coloration of these snakes is dark olive/black scales on top, pale scales on the belly. Younger cottonmouths have a more recognizable pattern to their scales, and a black mark above each nostril. However these marks fade over their lifetimes, giving way to a more solid, blackish color.


So do you want the good news or bad news first? Okay, so the good news about these snakes is they have the least potent venom of the North American pit vipers, and they’re distribution is limited.

The bad news… these snakes are responsible for more bites than any other US species. You might say they have a tendency to bite when they feel threatened, as opposed to rattling their tails or showing their fangs.

To the right is a map of the Copperhead’s range. They tend to live in wooded areas, rocky creek banks, and in wood piles.

The basic physical description of this snake is a pit viper with a striking cross-banded color pattern that usually has copper tones to it. There are several subspecies with varying colorations, but all species have a similar pattern, almost like a camouflage.

The base tone tends to be pale tan to almost a pinkish tan, with the dark brown “hourglass” pattern repeating from nose to tail.

Coral Snake

The coral snake has by far the most deadly venom of all North American snakes, a neurotoxin very similar to a cobra’s (they’re in the same family). On the bright side, they are notoriously reclusive and rarely bite humans.

Due to the placement of their fangs, these snakes must hold on for a few seconds and make a chewing motion to inject their venom. Thus, many bites don’t result in any venom injected at all.

In the old days, it’s estimated that 10% of coral snake bites resulted in death. Since the availability of the anti venom, there have been no recorded deaths from coral snake bites in the US.

Now, for the identification. These snakes stand out as entirely different from the others on this list, because they are not vipers. As I mentioned, they belong to the Elapidae family of snakes, which includes the cobra.

Unlike vipers, coral snakes don’t have especially large heads in proportion to their bodies. They are also very brightly colored, with a pattern of red and black stripes with yellow (sometimes white) bands in between.

In fact the same rhyme can be used to identify the vast majority of US coral snakes, “Red and black, friend of Jack. Red and yellow, kill a fellow.”

Several harmless species, e.g. the scarlet king snake look very similar to the coral snake to the novice. The distinguishing factor is the fact that it has red and black bands that touch. It’s red and yellow bands do not meet.


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  1. I have lived in Ariz. all my life. 61 years and come across many rattlesnakes in my time. Both in my own yard and out in the rocky hills and in the pine forest. They DO NOT ALWAYS RATTLE be for the strike. and i have killed them and after you think there dead they can still strike!!!!!! So always give them there space if your in there yard and if they are in your yard then take action…..

  2. To Bonnnie, thank you for your very valuable information. Would like to know if there is a book or other writing available about snakes ( including the GOOD ONES ) in the states of Florida, Georgia, and North and South Carolina. I am interested because these are the states we visit most of the time. Would appreciate if you have some information and You would e-mail it to me.
    Thanks again for your helpfull advice, yours truly, Sandor I. Nagy, Alpharetta, GA.

  3. Fr Christopher Kelley

    Most American rattlesnakes (Genus, Croatalus) have a blood-toxin, which causes the progressive swelling, then atrophy of the flesh of a limb that is bitten; but the “Mojave Green” rattler has a neurotoxin instead. I do not know if this puts it into a different Genus, or a different Family, from the others. Fortunately their range is quite limited; but those in the Mojave Desert area have to be specially alert to this species.

  4. Mega Doses of Vitamin C, injected will neutralize any venom, snake or spider.

    I’m a heating and cooling contractor and I had a business in Alabama and when in the Attics of home and businesses there were holes in the attic insulation and snake skins laying around. Not a good feeling.


  5. As accuracy is important, please note that rattlesnakes do not lay eggs. There was a brief comment on original email that referred to this. They are born “live” from an egg sack, not eggs as other species. Keep up the good work! Thank you

  6. The good news is that Copperheads and their cousin rattlesnakes are not aggressive. The woods around my house was infested with them, frequently found in my wood pile. Rather docile, you can even play with them once they learn you aren’t a threat. In 25 years I was bit once when I accidentally stepped on one, but he didn’t bother to inject any venom, so all was well. Guess he wanted to save his venom for something he could eat.
    BTW, a copperhead will shake its tail just like a rattle snake. In the leaves it sounds like a buzz. If you see or hear that, move away. And they travel in pairs. If you see one, another is usually nearby.

  7. I caught that in his article, I thought they were live bearers, thanks for confirming. Lived around Rattlesnakes for many years, we knew they were there but didn’t actually see them that often.

  8. Rattlesnakes are indeed live bearing snakes. Non-venomous snakes like the indigo snake do prey on young rattlesnakes, but not rattlesnake eggs (because there is no such thing)!

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