Denver’s Initiated Ordinance 301, passed by voters in May 2019, made adult personal use, possession, and home cultivation of psilocybin mushrooms the city’s lowest law-enforcement priority and barred Denver from spending public money to prosecute those offenses. It did not legalize the mushrooms. Selling them stayed a felony, public use stayed illegal, and federal law was untouched. Three years later, Colorado voters went much further at the state level, which is why the practical legal picture in Denver today is broader than what 301 alone accomplished.
What the Ordinance Changed
Ordinance 301 amended the Denver Revised Municipal Code to do three things. It designated the personal use, personal possession, and home cultivation of psilocybin mushrooms by people 21 and older as the lowest law-enforcement priority in the city.1Denverite. Initiated Ordinance 301 on the 2019 Denver Ballot: Decriminalizing Psilocybin Mushrooms It prohibited the city from spending resources to impose criminal penalties for those activities. And it created an 11-member policy review panel to evaluate the ordinance’s effects on public health and safety.
Decriminalization is not legalization. Selling psilocybin remained a felony, and public consumption was explicitly carved out of the measure.2The Guardian. Denver Votes to Decriminalize Psilocybin Mushrooms The mushrooms also remained a Schedule I controlled substance under both Colorado state law at the time and federal law, so federal authorities kept the power to prosecute possession and trafficking.3NPR. In Close Vote, Denver Becomes First U.S. City to Decriminalize Psychedelic Mushrooms
How the Vote Went
The initiative was sponsored by Decriminalize Denver, a grassroots group led by campaign director Kevin Matthews. In January 2019 the group turned in nearly 9,500 signatures to qualify the measure for the May ballot.4CNN. Denver Voters Approve Decriminalizing Psilocybin Mushrooms On May 7, 2019, Ordinance 301 passed with 50.56% of the vote, a margin of about half a percentage point.3NPR. In Close Vote, Denver Becomes First U.S. City to Decriminalize Psychedelic Mushrooms Election-night returns had briefly suggested the measure would fail before the final count reversed that projection.5Psychedelics Today. Denver Mushroom Decriminalization Denver became the first U.S. city to decriminalize psilocybin.
What Enforcement Looked Like Before and After
Even before the ordinance, psilocybin prosecutions in Denver were rare. The Denver District Attorney’s office had brought just 11 psilocybin cases out of more than 9,200 drug prosecutions between 2016 and 2018.2The Guardian. Denver Votes to Decriminalize Psilocybin Mushrooms
After the measure took effect, arrests fell further. The policy review panel’s 2021 report found psilocybin-related arrests dropped by more than half. Only five arrests in the period covered involved psilocybin alone, and three of those involved amounts beyond what would be treated as personal use. Most cases where mushrooms turned up also involved other drugs or offenses. The Denver Police Department and the District Attorney’s office both confirmed they were complying with the ordinance. Matthews, who chaired the review panel, said making psilocybin the lowest priority “hasn’t resulted in any significant public health or safety issues.”6Westword. Denver Panel Recommends Further Decriminalizing Mushrooms
What the Review Panel Recommended
The 11-member panel required by the ordinance included Denver County District Attorney Beth McCann (who had opposed the 2019 measure), Denver Police Division Chief Joseph Montoya, and Colorado State University associate professor of social work Shannon Hughes.7Los Angeles Times. Denver Dabbles With Magic Mushrooms
On November 9, 2021, the panel presented a report to Denver City Council finding no significant negative impact on public safety since the ordinance took effect, and it recommended:
- Making the non-commercial sharing (gifting) of psilocybin between adults the lowest law-enforcement priority.
- Extending that low-priority status to the supervision or facilitation of psilocybin use in group settings.
- Training Denver first responders to recognize and respond safely to people in a psychedelic crisis.
- Public education on safety, responsible use, and harm reduction.
- A system for monitoring public safety interactions involving psilocybin.
- Broadening the panel’s voting membership and adding a Denver Department of Public Health representative.
- Formally studying how psilocybin therapy could address mental health needs in Denver.
The Council discussed the recommendations but took no formal action at that session. Matthews said the panel planned to work with the Council on a first responder training pilot and pursue the remaining items in the following months.8Denver Gazette. Denver Panel Reports No Issues Since Decriminalization of Psilocybin Mushrooms
How Colorado Law Has Overtaken the Ordinance
In November 2022, Colorado voters approved Proposition 122, the Natural Medicine Health Act, which went well beyond Ordinance 301. The law decriminalized personal cultivation, possession, consumption, and non-commercial sharing of psilocybin, psilocin, DMT, ibogaine, and mescaline for adults 21 and older across the state. It also created a regulated framework for psilocybin-assisted therapy at licensed healing centers, overseen by two agencies: the Department of Regulatory Agencies handles facilitator licensing, and the Department of Revenue’s Natural Medicine Division licenses healing centers, cultivation facilities, manufacturers, and testing labs.9Colorado Department of Revenue. Natural Medicine Frequently Asked Questions
Colorado began accepting license applications on December 31, 2024, with first licenses expected in early 2025 and standard healing centers anticipated to open by summer 2025.10CPR News. Psilocybin Therapy Natural Medicine Healing Centers Coming to Colorado The framework distinguishes standard healing centers, which can store unlimited quantities of psilocin, from micro-healing centers designed as add-ons to existing mental health or wellness practices and capped at 750 milligrams of total psilocin.9Colorado Department of Revenue. Natural Medicine Frequently Asked Questions Clients must be 21 or older, complete a health screening, and go through a preparation session, a supervised administration session of five to 12 hours, and at least one integration session. Insurance does not cover these services.
In April 2026, Governor Jared Polis signed Senate Bill 26-31, which provides that if the DEA reschedules an FDA-approved psilocybin product, Colorado law will automatically align to permit dispensing of the pharmaceutical version. The bill explicitly preserves the Proposition 122 program as a separate track from any future prescription pathway.11Colorado Newsline. Psychedelic Medicines Colorado
Federal Law Still Applies
Psilocybin has been a Schedule I controlled substance under federal law since 1971, meaning it is classified as having a high potential for abuse, no currently accepted medical use, and no accepted safety under medical supervision.12Journal of the American Academy of Psychiatry and the Law. Psilocybin and Federal Law That classification did not change when Denver voted, and it did not change when Colorado voted. The Supreme Court’s 2005 decision in Gonzales v. Raich confirmed that the federal government retains authority to enforce the Controlled Substances Act even where states have legalized a drug.
The FDA designated psilocybin a “breakthrough therapy” for treatment-resistant depression in 2018 and for major depressive disorder in 2019, and in June 2023 the agency issued its first draft guidance on designing clinical trials for psychedelic drugs.12Journal of the American Academy of Psychiatry and the Law. Psilocybin and Federal Law If the FDA eventually approves a psilocybin product, the Attorney General would be required to issue an interim rule rescheduling the substance, likely to Schedule II. In April 2026, President Donald Trump signed an executive order aimed at accelerating FDA reviews of psychedelic mental health treatments.11Colorado Newsline. Psychedelic Medicines Colorado Until any of that happens, Denver’s ordinance and Colorado’s program both exist in tension with federal prohibition.
Same Name, Different Measures
Denver has used the “Initiated Ordinance 301” label for more than one ballot measure, which can cause confusion when searching. A 2018 Initiated Ordinance 301, called “Caring for Denver,” imposed a 0.25% sales tax to fund mental health and substance abuse treatment.13Denver Post. Denver Sales Tax Increase A 2021 Initiated Ordinance 301 required a citywide vote before any residential or commercial construction on city park land or property under a conservation easement, and it passed with more than 63% of the vote.14Colorado Politics. Citywide Vote on the Horizon for Denver Park Hill Golf Course Neither has anything to do with psilocybin. The psilocybin measure is the one from May 2019.