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  • Trevor Perkes

Are There Poisonous Insects or Snakes in Yellowstone?

We occasionally get emails from individuals that are planning their first trip to Yellowstone asking if there are poisonous insects or snakes that they need to be cautious about when in the park.

So, are there poisonous insects or snakes in Yellowstone? Yellowstone is not known to have black widow or brown recluse spiders or any other venomous spider. The only poisonous snake in Yellowstone National Park is the Prairie Rattlesnake. It is found, albeit rarely, in the norther part of the park near Gardiner, MT, in the lower Yellowstone River areas like Rattlesnake Butte, Stephens Creek, and Reece Creek. The likelihood of park visitors having a confrontation with the Prairie Rattlesnake is extremely unlikely. In the history of the park, there are only 2 reported incidences of venomous snake bites.

Most visitors to Yellowstone are aware of the various animals in the park that can be dangerous if you get to close to them. There are also those unique circumstances that can increase the risk for danger from animals such as startling a bear while hiking, coming upon a bear’s food stash, crossing paths with a sow bear and her cubs, and elk and bison during their respective ruts when hormones are raging, and behavior becomes more intense, aggressive, and unpredictable. Most people seem to believe that grizzly bear attacks are the greatest threat to humans when in the park, but since its establishment in 1872, the National Park Service (NPS) reports that only eight people have been killed by bears in Yellowstone. The NPS also notes that 7 individuals have died due to being struck by a falling tree.

Are there other insects that could pose a risk?

There are bees and wasps in the park that under the right circumstances could be of a concern, but rarely are. During the summer wildflower season the bees are more active. Yellow-Jackets are known to nest in the ground, sometimes invading rodent burrows or other vacated holes. If while hiking you look to take a rest break, simply look at the place you plan to sit to ensure it is free form any nest. Professional guide services (pack trips) in the park, like anywhere else, usually have an EpiPen in their supplies should a guest be stung, and an anaphylactic reaction occur. Most park rangers that are out among the people also are prepared for emergency situations.

Ticks are known to be in Yellowstone, and I have found them on my clothes at times when out hiking. Ticks tend to be more active in the spring and their activity will tend to decrease throughout the summer. These ticks generally take their time biting or burrowing into their host, so finding them if on your body should be easy with a little diligence. As such, it’s always a good idea to perform a head-to-toe check for ticks after spending outdoor time in an area where they are known to be.

What should I do if I find a tick embedded in myself of a family member?

There certainly are a number of ways that you have or can read about for removing a tick, but many are considered unsafe in that certain methods can result in the tick regurgitating or secreting salivate into victim. The Centers for Disease Control and Prevention (CDC) advises that if a tick is found attached to your skin you should remove it carefully and immediately. CDC directions for tick removal are:

1- Use fine-tipped tweezers to grasp the tick as close to the skin’s surface as possible.

2- Pull upward with steady, even pressure. Don’t twist or jerk the tick; this can cause the mouth-parts to break off and remain in the skin. If this happens, remove the mouth-parts with tweezers. If you are unable to remove the mouth parts easily with clean tweezers, leave it alone and let the skin heal.

3- After removing the tick, thoroughly clean the bite area and your hands with rubbing alcohol or soap and water.

4- Never crush a tick with your fingers. Dispose of a live tick by putting it in alcohol, placing it in a sealed bag/container, wrapping it tightly in tape, or flushing it down the toilet.

The CDC further admonishes to avoid folklore remedies such as applying nail polish, petroleum jelly, or essential oils to suffocate the tick and cause it to pull away or detach, a process that can take time and stress to the tick causing it to regurgitate or salivate into the skin. The goal is to REMOVE THE TICK AS SOON AS POSSIBLE. By properly and promptly eliminating the tick, you reduce the risk of contracting a tick born disease. The process of removal should be smooth and deliberate, as described above, to ensure that the tick’s mouth-parts or head are also successfully removed.

There are several tick removal tools available on the market. Many are intended for use on humans only, and some for use on humans and animals such as dogs, cats, and horses. Some come with built in magnification lens for an up-close look during your extraction procedure. The cost of these different devices can vary widely. Having a tick removal device in your basic first aid kit is a good idea for all your outdoor adventures.

What are the symptoms of a tick-borne disease?

Most symptoms of a tick bite don’t appear until three to 14 days after an infected bite occurs. And, because a person does not feel the bite of a tick, it may be burrowed into the person’s skin for days before it gets noticed, or it may not be noticed at all and dis-attach so the patient has no recollection of having a tick bite. Symptoms can include fever, chills, headache, muscle and skeletal pain, malaise, and possibly a “bulls-eye” appearing rash. If any of these symptoms appear you should go to your doctor who may start empiric treatment (e.g., antibiotics) immediately, even in the absence of a known tick bite, before the diagnosis of tick-borne illness is confirmed.

Are there other snakes in Yellowstone?

There is a total of five different species of snakes found in the boundaries of Yellowstone National Park. In addition to the venomous Prairie Rattlesnake mentioned above, the other four snakes are non-venomous. They are the Bullsnake, Rubber Boa, Common Garter snake, and Terrestrial Garter snake.

The Bullsnake, because of its appearance and behavior, is sometimes mistaken as a rattlesnake. If startled they will often coil up, swipe its tail against the ground, and sometimes make a hissing sound. But they are not poisonous, just capable of causing a little fear if you come upon them unexpectedly. The Bullsnake may be found near the North Entrance to the park, along the banks of the Gardner River as it flows north from just east of Mammoth.

Are there medical clinics located in Yellowstone?

There are three medical clinics within the park. They are located at Mammoth Hot Springs, Lake Village, and Old Faithful. Should an emergency occur to you when in the park, you can dial 911 or contact any park ranger. Eastern Idaho Regional Medical Center, located in Idaho Falls, Id, about 110 miles from the West Entrance is a top trauma center that works with Medcor to provide park visitors with medical services. You can check out our resource page topic titled "Medical Clinics" to learn more about the different medical services in Yellowstone. If your planning a trip to Yellowstone, be sure to explore our interactive map of Yellowstone by clicking HERE.

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