Apropos of the subject, let’s just sink our teeth into it: 2026 is likely going to be a big year for ticks in Colorado.
And that means, whether you’re out and about in the mountains, on the plains or in your yard, it could also be a big year for tick-borne illnesses, most of which are rare, fortunately, but none of which are fun.
There’s also some good news here: What’s usually thought of as the least-fun tick disease — that would be Lyme disease — is not carried by ticks that live in Colorado. But it is something that Coloradans traveling east need to be aware of.
We can see that you have more questions so we’ll, um, tick through them. (Sorry.)
Why is it going to be a bad tick season in Colorado?
As with so many other things this year, blame the winter that wasn’t.
Mild temperatures this winter throughout the state combined with warmer-than-usual weather in spring really got the party started on tick season, said Chris Roundy with the Colorado Department of Public Health and Environment. Roundy is a medical entomologist, which means he’s the state’s expert on bugs and the germs they can spread to humans.
“It just made it easier for ticks to survive the winter, and that warm weather gave them a head start on looking for hosts,” he said.
That’s it? One winter was all it took?
Well, not exactly. Remember back in 2023 when the state had an unusually wet spring?
Roundy said that’s a factor, too. The moisture allowed for grasses to grow tall, which is great habitat for ticks. The ticks responded to all that available housing by laying a bunch of eggs, which led to a bunch of new ticks.
“Ticks live for multiple years,” Roundy said. “That population boom is something we’re still dealing with.”
What ticks live in Colorado?
Yes, let’s meet the enemy.
Colorado primarily has two kinds of ticks: the American dog tick and the Rocky Mountain wood tick. Neither will ever win a beauty contest.
Though less common, Colorado also sees the brown dog tick, as well as other interlopers who — like a heat-addled Texan — don’t live here but love to travel to Colorado in the summer if given the chance.
“Ticks are really good hitchhikers,” Roundy said.
Where do ticks live in Colorado?
They live everywhere.
Like warring gangs, the American dog tick and the Rocky Mountain wood tick have largely divided the state down the middle, Roundy said.
The American dog tick is most likely to be found along the Front Range and on the plains to the east. The Rocky Mountain wood tick is most likely to be found in the mountains and to the west.
This is worth knowing because different ticks may transmit different diseases.
What diseases can I catch from ticks in Colorado?
There are two big ones that Roundy mentioned. One is called Colorado tick fever. The other is Rocky Mountain spotted fever.
But wait, there’s more! Ticks can also transmit tularemia, which is a bacterial disease that can also be spread through contact with infected animals, contaminated water or inhaling dust that contains the bacteria.
Then there’s tick-borne relapsing fever, which is a bacterial disease and is transmitted by an entirely different kind of tick called a soft tick, which is often associated with nesting rodents. People who stay overnight in rustic cabins may be vulnerable.
Lastly, there is tick paralysis, which is believed to be caused by a toxin in tick saliva and may occur when a tick is attached for long periods of time. People recover once the tick is removed.
Yeesh, how common are these diseases?
They’re quite rare.
Last year in Colorado, there were two cases of Colorado tick fever reported, six cases of Rocky Mountain Spotted fever and two cases of tick-relapsing fever. There were nine cases of tularemia reported, but it’s unclear how many of those were caused by ticks.
What is Rocky Mountain spotted fever?
It’s another bacterial disease, and it can be transmitted by the American dog tick and the Rocky Mountain wood tick.
It starts with a fever and headache, and a rash may develop two to four days after the fever. There’s no vaccine to prevent it, and it’s treated with antibiotics.
Here’s the big takeaway: If untreated, Rocky Mountain spotted fever can be deadly or can cause permanent damage — including amputation, hearing loss or mental impairment. If you’ve been bitten by a tick or even if you’ve just been in the woods or have been walking in brush and you develop these symptoms, see a doctor and let them know it might be tick-related.
Though associated by name with our region, Rocky Mountain spotted fever occurs more commonly to our east, with states like Missouri, Arkansas and Tennessee especially hard-hit.
What is Colorado tick fever?
It is a viral illness and is generally less severe than Rocky Mountain spotted fever.
The most common symptoms are cold-like: fever, chills, headache, body aches and fatigue. There is no vaccine and most people recover on their own, though symptoms may last several weeks. Roundy said it can be fatal in rare cases.
Colorado tick fever is spread primarily by Rocky Mountain wood ticks.
Is there Lyme disease in Colorado?
No. But also yes?
Lyme disease is spread by the deer tick, which is also known as the blacklegged tick. It’s this a-hole right here.
These ticks don’t live in Colorado. They basically stick to the Central time zone and points east. Roundy said one may randomly pop up from time to time in Colorado, but there are no known established populations. So, whew!
But Lyme disease is also the most commonly reported tick-borne illness for Coloradans each year. Last year, there were 47 cases, more than all other tick diseases combined.
Those cases come from instances of Coloradans traveling to other states and getting bit there. So, if you think you may have Lyme disease — fever, chills, aches, swollen lymph nodes and sometimes a bright red rash that may or may not look like a bullseye — be sure to let your doctor know your travel history.
What about the meat allergy thing? What’s that called?
Alpha-gal syndrome. Like a discarded villain from a Marvel movie.
Yeah, what’s the deal with alpha-gal syndrome?
It’s not a disease but a freaked out immune response.
Alpha-gal is a sugar molecule that is produced in the bodies of most mammals, but not humans. Roundy said ticks also have this molecule in their saliva.
When a tick bites a person, the molecule can get into the person’s blood, causing the immune system to see it as a threat and attack. That attack response can remain in place even after the tick is gone, so now the body starts attacking alpha-gal from food.
This means that person now has an allergy to red meat and dairy, plus some medicines or other products that contain alpha-gal. The allergy can be quite serious and require urgent care if triggered.
What ticks cause alpha-gal syndrome?
The actual dynamics of how the allergy is triggered aren’t known. Certainly not everybody bit by a tick develops it.
But Roundy said the most common culprit is the lone star tick, which has much greater concentrations of alpha-gal in its saliva than other ticks.
The lone star tick doesn’t live in Colorado, but it’s getting closer to our eastern border.
“The lone star tick has been expanding its geographic range pretty aggressively,” he said.
How can I protect myself from ticks?
Wear Environmental Protection Agency-registered insect repellant — these often contain DEET or picaridin. You can also treat your clothing in advance with permethrin. And be sure to give yourself a tick check after walking in tall grass or through the woods.
Roundy said ticks love crevices and other places where there’s something to grab hold of. So check armpits, the backs of knees, the groin, the waistline and belly button, in and around the ears and in the hair. A buddy can help with hard-to-see places.
Also be sure to check your clothes and gear for ticks that may sneak up on you later. And check your dogs, too. Lastly, showering after being outside may help wash off unattached ticks.
If you find a tick that’s already dug in, this guide by the Centers for Disease Control and Prevention can help you remove it.
What else can I do?
You can become a tick spy.
Colorado has a program where people who find a tick can send it in for identification. This helps the state track what ticks are where. Use this form to submit your tick.
The state has also begun conducting more active tick surveillance in at least 25 participating counties to get a more complete understanding of the pre-tick-ament.
Ugh.
That didn’t tick-le your funny bone?
Seriously, no more puns.
OK, fine. Thanks for following our tick talk.