Venomous Snakes of Idaho

Prairie Rattlesnake

The only venomous snakes in Idaho are rattlesnakes.

Idaho is home to the Prairie Rattlesnake and the Western Rattlesnake. There are two subspecies of western rattlesnakes in Idaho. These are the Northern Pacific Rattlesnake and the Great Basin Rattlesnake.

We’ll talk about each of these Idaho rattlesnakes in the paragraphs below. We’ll tell you what these snakes look like, how dangerous they are, and where they live in Idaho.

Pit Vipers

Rattlesnakes belong to the venomous Viperidae or pit viper family. Pit vipers have heat-sensing pits between their nostril and eyes on each side of their face. These pits are specialized organs that detect infrared radiation from prey animals. Pit organs enable pit vipers to strike their prey precisely, even in the dark. They are also able to detect body heat from about 1 meter away.

These snakes also have triangular-shaped heads. Furthermore, the pupils of their eyes are vertical elliptical slits. This is a defining characteristic because a nonvenomous snake generally has round pupils.

Pit vipers have hollow fangs connected to venom glands. They use their fangs to inject venom into their prey. This venom immobilizes the prey, making it easier for the snake to consume. They primarily consume small mammals, reptiles, amphibians, and small birds. These snakes play an important role in maintaining balance in rodent populations.

Rattlesnakes

The first thing people think about with regard to Rattlesnakes is their tails. When they are disturbed, they vibrate the rattles on their tails. This makes a buzzing or a rattling-type sound. Sometimes, rattlers strike without rattling. Sometimes, their rattles fall off. You must be aware of where you are placing your hands and feet in rattlesnake country. If you hear a rattling noise, do not move until you spot where it originated. Otherwise, you may accidentally move into the snake, allowing it to strike you.

Northern Pacific Rattlesnake photo by Connor Long CC BY-SA 4.0

Northern Pacific Rattlesnake (Crotalus oreganus)

Another name for the Northern Pacific rattlesnake is the Western rattlesnake.

These snakes can grow to 39 inches (99cm) long. The longest Northern Pacific rattlesnake on record is 64 inches (163cm). Their base color varies. They are dark brown, dark gray, and sometimes black. Their base color is interspersed, with a covering of dark blotches with lighter edges. These lighter-edged blotches turn into crossbands at the tail. The last two crossbands at the end of their tail are generally black. Their bellies are pale yellow with brown spots. There is a dark brown stripe with a light border extending from its eye through the angle of the jaw.

Where Do Northern Pacific Rattlesnakes Live in Idaho?

The Northern Pacific Rattlesnake is found in west-central Idaho. Along the Clearwater, Salmon, and Snake River drainages. They’re the only rattlesnakes in the Treasure Valley and the Boise foothills. Watch for these snakes in dry, rocky areas.

Gopher snakes inhabit a lot of the same territory that rattlesnakes do. Their territory includes the Boise Foothills. They are marked similarly to rattlesnakes and do a pretty good job of mimicking them. When gopher snakes are defensive, they sometimes vibrate their tails like rattlesnakes do. They also flatten out their heads to imitate the triangular head of a rattlesnake.

How Dangerous Are Northern Pacific Rattlesnakes?

Northern Pacific rattlesnake venom has neurotoxic properties, along with hemotoxins and myotoxins.

Envenomation from one of these snakes may cause a multitude of symptoms. These include pain, swelling, fatigue, muscle weakness, body aches, and joint pain. In some cases, enlarged lymph nodes, anxiety, drowsiness, nausea, and diarrhea occur. Some of the systemic symptoms include neurological symptoms, internal hemorrhaging, and kidney failure. Source

Great Basin Rattlesnake photo by Morgan Hansen CC BY 4.0

Great Basin Rattlesnake (Crotalus oreganus lutosus)

The Great Basin Rattlesnake is a subspecies of the western rattler. See,

These snakes’ bodies are light grey or light brown. Their bodies are also covered with dark blotches. These blotches are dark brown to black with pale centers. These rattlesnakes rarely exceed 3 feet (.91 m) in length. However, the largest specimens grow to 4 feet (1.22 m).

Where Do Great Basin Rattlesnakes Live in Idaho?

The Great Basin Rattlesnake inhabits parts of southern Idaho below 44° N latitude. For reference, Saint Anthony is just under 44° north latitude in eastern Idaho. On the other hand, in western Idaho, Payette is just over 44° north latitude.

Great Basin Rattlesnakes live in the dry, barren landscape of the Great Basin. They can be in mountainous areas up to 11,000 feet above sea level. However, they’re most common below 8,000 feet. They live in a variety of habitats. These include juniper forests, sagebrush flats, and dry rocky hillsides.

How Dangerous Are Great Basin Rattlesnakes?

The Great Basin rattlesnake has a potent venom. It is a potent mix of myotoxins and hemotoxins. Their bites may produce pain, edema, nausea, and vomiting. Furthermore, the hemotoxic part of their venom can cause internal bleeding. This may lead to multiple organ damage. Moreover, the myotoxic part of their venom will produce necrosis of body tissue. Source

Prairie Rattlesnake

Prairie Rattlesnake (Crotalus viridis)

Adult Prairie rattlesnakes average around 3.3 feet (100 cm) in length. The longest recorded specimen measured just under 5 feet (151.5 cm) long. They are tan-colored with varying colors of brown blotches covering their bodies. They have a distinguishing triangle-shaped head with pit sensory organs on either side. A light stripe runs diagonally from the back of its eye to its jaw. Another strip runs diagonally from below its eye to the corner of its mouth. Prairie rattlesnakes are mostly ground snakes. But they occasionally climb into shrubs, bushes, or trees.

Prairie Rattlesnakes brumate in communal dens. But their hunting grounds extend as far as seven miles from their dens in the summertime. In the warmer months, prairie rattlers might shelter in old mammal burrows. But in the fall, they will return to their communal dens.

Where Do Prairie Rattlesnakes Live in Idaho?

The Prairie Rattlesnake is found in Lemhi and Valley counties. These are in east-central Idaho. They also live in northeastern Idaho, along the Montana border. The Frank Church Wilderness Area rattlesnakes are prairie rattlesnakes. This is according to the Idaho Department of Fish and Wildlife.

Prairie rattlesnakes live in open prairies, arid grasslands, and mountainous terrain.

How Dangerous Are Prairie Rattlesnakes?

Prairie rattlesnake venom is a mix of hemotoxins and myotoxins. Furthermore, according to some literature, it also has neurotoxins.

Prairie rattlesnake bites can have serious effects. The venom can cause severe pain. It may also induce shock, making the victim feel weak and disoriented. Swelling, blistering, and inflammation can occur at the bite site. Their venom can also damage red blood cells and impair blood clotting. In severe cases, the bite may result in severe tissue damage. There is also a risk of harm to internal organs. Source

Symptoms of Venomous Snake Bites

Some of the symptoms you may experience from a venomous snake bite include:

  • Discoloration in the area of the bite.
  • Swelling in the area of the bite.
  • Loss of muscle coordination.
  • Tingling sensation in the area of the bite.
  • Feeling nauseous.
  • Having an abnormally rapid pulse.

What Should You Do If A Venomous Snake Bites You?

If you or someone you are with has suffered a venomous snakebite, time is of the essence. The sooner a victim receives antivenom, the less likely the venom in their body is to cause harm. In other words, it is important to seek immediate medical attention.

Do not attempt to kill the snake for identification purposes. This gives the snake a chance to bite you again. Also, consider that severed snakeheads can still bite and envenomate. If you have a phone, take a picture of the offending reptile. Otherwise, get started on your way to the nearest hospital.

First Aid for Snake Bite Victims

  • Remain calm and limit your movements. Do not run. If you must hike back to a vehicle, do it calmly and deliberately. Put as little stress on your heart as possible.
  • Keep the area of the snake bite below the heart level and never above the heart level. Keeping the bite below the heart level will reduce the venom’s flow. However, holding the bite above your heart level will increase the venom’s flow.
  • Remove all constricting items such as bracelets, watches, or rings before swelling occurs.
  • Remember that using a cold compress on a venomous snake bite is not advisable. The cold may cause the local blood vessels to constrict and spread the venom faster.
  • You can wash the affected area like any other wound with soap and water.
  • You may cover the bite area with a moist dressing to reduce the swelling.
  • Get medical attention as soon as possible. Call the hospital to tell them a venomous snake has bitten you. So they can have antivenom ready to give you when you arrive.
  • A person whom a venomous snake has bitten may go into shock. If this happens, lay them flat and cover them with a blanket.

Antivenom Price For Treatment of Snake Bite in Idaho

To manufacture antivenom, they must first milk venom from a live snake. Then, they inject that venom into donor animals like horses or sheep. Next, they harvest the antibodies that these animals produce. That’s a simplified version of the complicated process involved in manufacturing antivenom.

Antivenom is expensive to produce. But, it’s a vital life-saving therapy for some individuals who have been bitten by venomous snakes.

The two main antivenom therapies that cover pit viper venoms in the U.S. are CroFab and Anavip.

When a patient undergoes antivenom therapy, the doctor administers a minimum starting dose. More vials of antivenom will be added depending on the severity of envenomation.

The average cost of crotalidae polyvalent immune fab ovine or CroFab is $3,198 per vial. The recommended starting dose is 4 to 6 vials.

The average cost of Crotalidae immune F(ab’)2 (equine) or Anavip is $1,220 per vial. The recommended starting dose is 10 vials. Source

The type of antivenom in use varies between different healthcare providers. Also, note that the prices listed above do not reflect the total cost of the treatment. They are the average wholesale price for vials of snake antivenom. In other words, they are what healthcare providers pay.

Dressing for rattlesnake country

  • High-top leather boots and long pants are both wise ideas.
  • Also, wear loose-fitting denim. If there’s a gap before the snake’s fangs touch your skin, your chances of being envenomated are lower.
  • In the absence of high-top leather boots, some people wear snake gaiters.

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