Texas vs. California: Which State Has More Venomous Snakes?

Written by Gail Baker Nelson
Updated: May 26, 2023
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Key Points to Knowing Whether There Are More Venomous Snakes in Texas or California:

  • There are more venomous snakes in Texas than in California.
  • California’s native venomous snakes are all rattlesnakes.
  • Texas has rattlesnakes, coral snakes, copperheads, and cottonmouths.

Texas and California are two of the three biggest states in the United States, with 268,581 and 163,696 square miles, respectively. Of course, they’re both dwarfed by Alaska with over 586,000 square miles. However, since Alaska doesn’t have any native snakes, it doesn’t figure into our discussion today.

After all, we wanted to know which state has more venomous snakes: Texas or California. We used iNaturalist.org for the numbers. Although not perfect, it’s a fantastic resource for learning to identify snakes in your area and contribute to scientific research.

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To figure it out, we looked at how many venomous species inhabit each state. Also, we left out mildly venomous snakes like the lyre and garter snakes. They aren’t medically significant to anything but their prey, leaving us safe from what amounts to mildly toxic saliva.

Without further ado, let’s explore!

California: 8 Venomous Snake Species

Although you may expect to see more than eight venomous snakes in California, you’d be disappointed. The Golden State only boasts eight native species and they’re all rattlesnakes.

We love that California’s danger noodles all come with an early warning system. However, rattlesnakes don’t always rattle a warning. Sometimes they’re startled and lash out without warning, but some don’t have a rattle. Baby rattlesnakes don’t have a rattle until a couple of sheds after they’re born. And there are the odd rattlesnakes that lose all or most of their rattle in a death match or by getting it caught in the brush or rocks as they travel.

In any case, here are California’s most notorious venomous snakes:

The Most Common Rattlesnakes in California: Northern and Southern Pacific Rattlesnakes (Crotalus oreganus and Crotalus helleri)

Southern pacific rattlesnake

Southern Pacific rattlesnakes inhabit coastal and some inland areas in the southwestern corner of California and northern Baja California.

©Audrey Snider-Bell/Shutterstock.com

Until a few years ago, these and several other rattlesnake species were counted as subspecies of just one or two. Genetic testing showed that they were distinct species, so now many sources break them out as separate species. However, not all do this yet.

Adding to the confusion, the species regularly breed amongst each other in the region where the two species’s territory overlaps.

Northern Pacific rattlesnakes are also called western rattlesnakes and average about three feet long, although they can reach four. They have a typical rattlesnake head with large venom glands behind the eyes and a thin neck. Roughly hexagon-shaped blotches grace their dorsal side down the length of their backs, which become dark wide rings with narrow light cross bands near the tail.

In contrast, their southern Pacific rattlesnake cousins have more diamond-shaped blotches and darker contrasting colors. Their blotches have lighter borders and may or may not have a lighter center. Their tail rings aren’t as well-defined.

Which snake bites more?

In California, you’re far more likely to encounter northern and southern Pacific rattlesnakes, depending on whether you’re north or south of Santa Barbara. They’re widespread and occur in almost every type of habitat. While they tend to avoid housing and commercial developments, finding one in a more rural yard or cliff overlooking the ocean is common.

Some believe that the northern and southern Pacific rattlesnakes bite more people in California than other species, but we couldn’t find specific references to support the idea. The reality is that when people go to the hospital, all they usually know is that it was a rattlesnake. Most people won’t sit and count scales or check the pattern for a positive identification. We can make educated guesses based on where the individual was when they were bitten, but there are limits. However, their wide range in the state gives the claim some validity. 

Red Diamond Rattlesnake (Crotalus ruber)

Coiled red diamond rattlesnake

Red diamondback rattlesnakes coil up, rattle, and may strike when they’re threatened.

©Creeping Things/Shutterstock.com

This species is the second-largest in the state, after the western diamondback rattlesnake. Considering their small range in California, red diamond rattlesnakes are encountered with startling regularity.

Red diamond rattlesnakes only inhabit southern California but have the third-most sightings of rattlesnakes logged in iNaturalist.org. They grow up to five feet long and, true to their name, have reddish diamond-shaped blotches on their backs, ending in black and white bands around the tail near their rattles.

Although they’re mild-mannered and don’t bite often, these snakes are capable of delivering a lot of venom in one bite, an average of 364mg.

The Most Dangerous Rattlesnake Venom: Mojave Rattlesnake (Crotalus scutulatus)

Mojave rattlesnakes are one of very few rattlesnakes that have neurotoxic venom in large quantities. Interestingly, there are two base venom groups — venom A and venom B. 

Venom A snakes have an additional toxin in their venom called Mojave toxin that makes their venom more than 10 times more toxic than the venom B group. Guess which one is more common in California? If you guessed venom A, you’re correct. 

Sometimes called Mojave greens because they often have a green hue to their color, combined with a pronounced diamond pattern. They get mistaken for diamondback rattlesnakes because of their pattern and behavior — they look similar and are also very nervous snakes. However, these are probably the most dangerous rattlesnakes to encounter in California.

Fortunately, California’s Mojave rattlesnakes live in remote, rocky desert areas far away from most people in the state’s southeastern edge. They also occur in far southwestern Texas, where people often misidentify western diamondbacks as Mojave rattlesnakes.

Western Diamondback Rattlesnake (Crotalus atrox)

Of the other four rattlesnakes in California, only one is notorious for biting. Western diamondback rattlesnakes are big — the second biggest behind eastern diamondback rattlesnakes. They’re also really nervous. People often say that they’re aggressive, but an aggressive animal will hunt you down. Western diamondback rattlesnakes will flee if given even a quarter of a chance. They’ll also rattle and hiss as they flee. 

In reality, they’re cowards. 

Unfortunately, their nervous nature also makes they highly likely to bite. Their size means they can inject a lot of venom. Although they’re dangerous, these snakes only occur in the far southeastern corner of California near the Arizona border.

Other California Venomous Snakes

Here are the other venomous snakes in California, in order of the number of sightings logged into iNaturalist.org:

  • Southwest speckled rattlesnake (Crotalus pyrrhus)
  • Sidewinder (Crotalus cerastes)
  • Panamint rattlesnake (Crotalus stephensi)

Texas: 12 Venomous Snake Species

Where California had eight cute but slightly scary rattlesnakes, the Lone Star State had to outdo them with 12 venomous snakes, including North America’s only native elapid species. We’re not counting the odd sea snake that sometimes washes ashore dead or dying on California coasts.

Western Diamondback Rattlesnake (Crotalus atrox)

coiled western diamondback rattlesnake

Western diamondback rattlesnakes coil up and rattle their tails to discourage predators.

©Audrey Snider-Bell/Shutterstock.com

Wait, wasn’t this snake in California too? Yes! Western diamondback rattlesnakes have a huge range across the American Southwest. While their range only extends into a small corner of California, these cowardly danger noodles are the most common venomous snake in Texas. Even if you combine the two copperhead species into one number, there are still more western diamondback sightings in Texas.

Although big, this rattler matches its surroundings and you’ll have trouble spotting it. You’re more likely to hear it before you ever see a western diamondback rattlesnake. Its diamonds aren’t as dramatic as its eastern cousin, and the sandy-brown base color helps it camouflage nearly perfectly. Western diamondback rattlesnakes have big, spade-shaped heads and vertical pupils. They average between three and six feet long and, like other pit vipers, have heat sensing pits between their eye and nostril. 

Western Diamondback rattlesnakes are extremely nervous and rattle and the smallest provocation. They’re the most likely to give you a warning while they look for an escape route. Unfortunately, if they don’t think you’re leaving them alone quickly enough, they’re also more likely to bite. 

Cottonmouth (Agkistrodon piscivorus)

Moccasin Snake

Cottonmouth crossing a dirt road showing mouth, Agkistrodon piscivorus

©Nathan A Shepard/Shutterstock.com

The dreaded water moccasin, also called the cottonmouth, is not the monster it’s made out to be. It’s the second on our Texas list because of sheer sighting numbers. 

Cottonmouths can reach six feet long, but most never exceed four feet. Even so, these snakes are thick-bodied and have big, angular heads. Their eyes have vertical pupils and dark, black stripes extending diagonally from behind their eyes. 

Young cottonmouths have chocolate kiss patterns on their sides over a lighter brown to tan color. Also, they have bright yellow to green tail tips. While this is similar to copperheads, they’re easy to tell apart because pattern the edges are jagged and rough, unlike a copperhead’s pattern. Also unlike copperheads, cottonmouths lose their pattern almost completely as they age. They become a big black to olive brown snake, but their dark eye stripe remains. 

A semi-aquatic species, water moccasins are never far from water. They feed on fish and amphibians, but won’t turn down small rodents. This species, while highly venomous like the other snakes on our list, doesn’t bite as many people.

Copperhead (Agkistrodon contortrix and Agkistrodon laticinctus)

The Copperhead’s scales are keeled, and their eyes have vertical pupils that make them resemble cat’s eyes.

The Copperhead’s scales are keeled, and their eyes have vertical pupils that make them resemble a cat’s eyes.

©Creeping Things/Shutterstock.com

Until a few years ago, copperheads were lumped together into one species with about five subspecies. With modern genetic testing, however, they’re separated into two species — it’s actually simpler to track now. Both species occur in Texas. 

Although they’re in the same genus as cottonmouths, copperheads are smaller and rarely exceed three feet long. In looks, both copperhead species are undeniably copperheads — dark cross bands with clean edges over a lighter base color and copper-colored heads. The biggest difference between the two is in the style of cross bands. Broadband copperheads have wide cross bands that only slightly narrow at the spine. Eastern copperheads have the traditional hourglass-shaped markings that many people describe as chocolate kisses from the side. 

Experts say that their venom isn’t as dangerous as the other pit vipers that may bite you, even though it’s a cytotoxic venom. However, although these snakes bite approximately 3,000 people every year, it’s almost never fatal — assuming they inject any venom at all. However, unlike most venomous snakes, copperheads don’t have any issues living near people. Fortunately, they’re relatively docile and only bite when they’re directly harassed or stepped on.

In order of sightings via iNaturalist.org, here are the rest of Texas’ venomous snakes:

When are Snakes Most Active

Like us, snakes love spring and summer weather. When it’s warm and beautiful, these cold-blooded critters to sun themselves and actually digest food. Unlike us, snakes need help from the environment’s warmth to support their bodily functions. When it’s too cold, food literally rots in their stomach.

So, just when you think it’s a great day to get out into the sun for a hike, so do the snakes.

In both states, snake season begins around March and ends when they head off to brumate around October. However, the more southern and coastal areas of Texas may have snake activity year-round. During the spring and fall, snakes can be active all day long, but when the summer heats up they switch to early mornings and late evenings. Just like us, they can overheat, so they adjust their activities accordingly.

What to Do If You’re Bitten

Venomous snakebites are no joke. If you are bitten by a venomous snake, go to the hospital. Although as many as 50% of all snakebites are dry — without venom — you don’t immediately know if that’s the case. Additionally, some snake venom can take hours to show the full damage, and at that point, it’s too late to help you save a limb or a life.

Here’s basic first aid until you can get there:

  1. DO immobilize the part bitten. A sling if it’s a hand or arm, a leg is harder to immobilize, but try.
  2. DO remove all jewelry, especially watches and rings. Venom often causes massive swelling, get these things out of the way or you’ll have more tissue damage AND some jewelry repairs.
  3. DO keep calm. Keeping your blood pressure down will slow the spread. Besides, panicking never helps.
  4. DO keep the part bitten at or below the level of your heart if at all possible.

Prevent more damage

Of course, there’s a list of things you should avoid. Most of this is pretty basic, but hey — it’s good to have a reminder!

  • Do NOT CAPTURE THE SNAKE. You’ll probably get bitten again. If the first bite was dry, the second bite will likely envenomate you. Instead, try to get a photo or memorize what it looked like. North American snakebites either use polyvalent antivenom for pit vipers or a separate one for coral snake venom.
  • DO NOT use tourniquets. Recent research indicates that they don’t slow the venom’s spread, and applied incorrectly will damage tissue.
  • DO NOT apply ice.
  • DO NOT drink alcohol or caffeine. They thin your blood, speeding the damage caused by the venom, which often causes clotting issues and internal bleeding.
  • DO NOT try to suck out the venom. It’s a waste of time because they inject it too deeply.

Complete List with Sightings and Danger Level

Here’s our list of the venomous snakes in both states, complete with the number of sightings people have reported on iNaturalist.org and the danger level. We determined the danger level based on both the venom and the likelihood of the snake biting.

Species NameCaliforniaTexasDanger Level
Western Diamondback (Crotalus atrox)1188,239Very high. Nervous snake more likely to bite and inject venom than other snakes.
Southern Pacific Rattlesnake (Crotalus helleri)7,7960High. Common snakes in their range. 
Northern Pacific rattlesnake (Crotalus oreganus)6,6350High. Their wide range makes you more likely to encounter one. 
Northern cottonmouth (Agistrodon piscivorus)04,583Medium to high. They don’t bite as often as copperheads, but their venom is more dangerous.
Eastern copperhead (Agistrodon contortrix)03,296Medium, but most bites are minor.
Broad-banded copperhead (Agkistrodon laticinctus)02,612Similar to eastern copperheads.
Red diamond rattlesnake (Crotalus ruber)2,4150Medium to high. They’re docile for rattlesnakes and bites rarely, but they can inject a massive amount of venom.
Texas coral snake (Micrurus tener)02,367High. If bitten, extremely dangerous, but bites are rare.
Southwest speckled rattlesnake (Crotalus pyrrhus)1,4220Medium to high. 
Sidewinder (Crotalus cerastes)1,3850 Medium
Black-tailed rattlesnake (Crotalus ornatus)01,005 Medium
Mojave rattlesnake (Crotalus scutulatus)507728Very High. Venom A snakes have an extra toxin.
Timber rattlesnake (Crotalus horridus)0555High. Lots of venom but bites rarely.
Prairie rattlesnake (Crotalus viridis)0538 Medium to high
Rock rattlesnake (Crotalus lepidus)0474Medium to high 
Western massasauga (Sistrurus tergeminus)0357High. Small snake with less venom but more inclined to bite.
Panamint rattlesnake (Crotalus stephensi)1970Medium, very rare
Pygmy rattlesnake (Sistrurus miliarius)077Medium if encountered. Rare snake, very shy.

The photo featured at the top of this post is © Alexander Wong/Shutterstock.com

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About the Author

Gail Baker Nelson is a writer at A-Z Animals where she focuses on reptiles and dogs. Gail has been writing for over a decade and uses her experience training her dogs and keeping toads, lizards, and snakes in her work. A resident of Texas, Gail loves working with her three dogs and caring for her cat, and pet ball python.

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