A dangerous killer is still creeping across the United States, according to U.S. Drug Enforcement Administration officials, and many may not even see it coming.

The Rocky Mountain division of the DEA, which covers Colorado, Utah, Wyoming and Montana, has seized tens of millions of fentanyl doses since 2021.

Officials estimate as much as 29% of the pills seized by the DEA contain a fatal dose of the drug, which can be as small as two milligrams. Officials estimate hundreds of thousands of lives have been saved by the seizures.

And while fentanyl deaths are down nationwide, they’re up in Colorado by 10%, with 1,800 people dying from fentanyl overdoses last year. In Denver, fentanyl deaths rose 25% last year to 346, up from 277 the year before, according to the Denver Department of Public Health and Environment.

Wednesday is Fentanyl Awareness Day, the fifth time such a day has been recognized. It’s part of a push by the DEA to educate the public about the dangerous drug, which has climbed in recent years to represent a large percentage of overdose deaths. 

A big part of what makes illicit fentanyl so dangerous is its potency and how many illicit drugs are being cut with it, officials said.

An opioid used normally as a painkiller in hospitals, it is about 50 times more potent than heroin and 100 times more potent than morphine, and many manufacturers of counterfeit pills will put fentanyl in the pills, which can often appear to be oxycodone, Percocet, or even Xanax.

Officials said fentanyl has been found in cocaine, heroin and methamphetamine. The drug is also cheap, with pills ranging from $1 to $5, and can be easily found through dealers selling them on social media.

David Olesky, special agent in charge of the DEA’s Rocky Mountain division, said at a news conference Tuesday that while 6.7 million fentanyl pills were seized last year across the four Rocky Mountain states, illicit fentanyl powder has begun to creep into the market in Colorado.

Officials estimate that, combining pills and powder seized, as much as 7.5 million doses of fentanyl were seized in Colorado alone in 2025.

Olesky said more than half a million pills have been seized this year already.

With overdose deaths up in Colorado, he said more drug education is needed in schools and more accountability needs to be had in the court system for drug traffickers.

“I’m not someone who yells, but the overdose deaths here in the state of Colorado are screaming for attention,” Olesky said. “The most recently released national overdose death numbers, per the CDC, show an 18% national decline, while the state of Colorado has a 10% increase in deaths year over year.”

Olesky said Mexican drug cartels, namely the Sinaloa and CJNG cartels, are responsible for the majority of fentanyl coming into the United States. Both groups have been designated foreign terrorist organizations by the U.S. government.

Peter McNeely, U.S. attorney for the District of Colorado, said his office has an entire section dedicated to combating illicit fentanyl and reducing its presence in Colorado.

He said the U.S. Attorney’s Office is constantly conducting investigations into the cartels’ trafficking of fentanyl into the United States.

Due to the amount of fentanyl making its way into street drugs, McNeely warned people to only take drugs prescribed by a doctor.

“There are no drugs that are safe in our community these days, except those that come straight from a physician or from a pharmacist,” he said.