Decriminalize Denver — in 2019 Denver became the first US city to decriminalize psilocybin mushrooms.
Denver Initiative 301 made personal psilocybin use the city's lowest law-enforcement priority for adults 21 and older. Denver voters approved the measure, officially called Initiated Ordinance 301, on May 7, 2019. It made Denver the first US city to decriminalize psilocybin mushrooms.
The ordinance does three things. It makes adult personal use and possession the lowest priority for police. It bars the city from spending money to impose criminal penalties for that use. And it set up a panel to study the effects.
The win was barely a win. The measure trailed on election night, then flipped the next afternoon when Denver Elections released the final count. It passed with about 50.6% — roughly 89,320 yes votes to 87,341 no, a margin of fewer than 2,000 votes. That razor-thin result, not a landslide, is what launched the national movement.
Initiative 301 was the spark for a wave of city and state reforms. After Denver, cities like Oakland, Santa Cruz, and Washington, D.C. followed, and Colorado went statewide three years later. For the full national picture, see our roundup of cities that decriminalized psilocybin. This page stays focused on Denver itself.
Decriminalization and legalization are not the same thing, and Denver Initiative 301 did only the first. Decriminalization lowers or removes enforcement, but the substance stays illegal. Legalization builds a legal, regulated market where you can buy and sell.
This difference is the single most misread fact about 301. The table below shows exactly what the measure did and what it left untouched.
| What people ask | Decriminalization (what 301 did) | Legalization (what 301 did NOT do) |
|---|---|---|
| Is personal possession still a crime? | Still illegal, but lowest police priority for adults 21+ | Would be fully legal with no penalty |
| Can you buy mushrooms in a store? | No — no legal sale created | Licensed retail or dispensaries would exist |
| Can businesses sell or grow commercially? | No — commercial activity stays illegal | Regulated commercial market with licenses |
| Does it change state or federal law? | No — city ordinance only | Would require state or federal legalization |
| Verdict | Police de-prioritize adult personal use | Not what Denver voters approved in 2019 |
In short, 301 told Denver police to stop treating adult personal use as a priority and told the city to stop paying for those prosecutions. It did not build a legal market. For the broader question of where mushrooms are legal across the US, see our legal status by state tool.
After Initiative 301, Denver adults 21 and older faced the lowest risk of arrest for personal psilocybin use of any US city at the time. But the change was limited and specific. Knowing the limits matters.
Denver's official policy review panel found that decriminalization caused no significant public-safety problem. Initiative 301 created the Psilocybin Mushroom Policy Review Panel to study the measure's effects. The panel delivered a comprehensive report to the Denver City Council in 2021.
This is the information most readers never see: the city studied its own experiment and the data pointed one way. The panel concluded that decriminalizing psilocybin mushrooms in Denver "has not since created any significant public health or safety issue in the city."
The panel did recommend public-education messaging, harm-reduction access, and training first responders to handle a psychedelic crisis. That mix — no measured harm, plus a call for better support — is the real-world record other cities later cited when weighing their own measures.
Denver Initiative 301 and Colorado Proposition 122 are often confused, but they are very different laws. Initiative 301 (2019) is a city ordinance covering only psilocybin inside Denver. Proposition 122 (2022) is a statewide law covering five natural psychedelics with a regulated program.
If you want the full statewide picture, including licensed healing centers, read our Colorado Proposition 122 guide. Here is how the two compare at a glance.
| Feature | Denver Initiative 301 (2019) | Colorado Prop 122 (2022) |
|---|---|---|
| Scope | City of Denver only | Entire state of Colorado |
| Substances | Psilocybin mushrooms only | Five natural psychedelics |
| What it does | Lowest police priority for adult personal use | Decriminalizes possession statewide |
| Regulated access | None created | Licensed healing centers |
| Legal type | City ordinance | State statute |
Today, a Denver adult is covered by both: the local 301 priority and the broader statewide Prop 122 decriminalization. Prop 122 is the law that now does the heavy lifting across Colorado. To learn more about the substance itself, see our psilocybin guide.
Denver Initiative 301 started a national decriminalization wave. Before 301, no US city had decriminalized psilocybin. Within weeks, Oakland moved, and dozens of cities followed over the next few years.
One of the most-watched followers was Washington, D.C., where voters passed DC Initiative 81 in 2020 — a broader measure covering many natural psychedelics. Denver's narrow win and its later clean safety record gave those campaigns a model to point to.
Denver Initiated Ordinance 301 made personal use and possession of psilocybin mushrooms by adults 21 and older the lowest law-enforcement priority in Denver. It also barred the city from spending resources on criminal penalties for that personal use, and it created a policy review panel. It did not legalize sale, retail, or commercial activity.
Denver voters approved Initiated Ordinance 301 on May 7, 2019, with results certified the next day. The measure passed by a razor-thin margin of about 50.6%, making Denver the first US city to decriminalize psilocybin mushrooms.
No. Initiative 301 decriminalized personal use and possession for adults 21+, it did not legalize psilocybin. The substance stayed illegal under Colorado state law and Schedule I under federal law. Selling, buying in a store, and commercial activity remained illegal.
Decriminalization lowers or removes the priority of enforcement but the substance stays illegal. Legalization creates a legal, regulated market with licensed sale. Denver Initiative 301 decriminalized personal psilocybin use; it did not create any legal way to buy or sell mushrooms.
No. Denver's official Psilocybin Mushroom Policy Review Panel reported in 2021 that decriminalization created no significant public health or safety issue. Mushroom-related arrests fell, hospitals reported no mushroom emergencies, and there were no recorded fatal overdoses.
Denver Initiative 301 (2019) was a city ordinance that decriminalized only psilocybin mushrooms inside Denver. Colorado Proposition 122 (2022) is a statewide law that decriminalized five natural psychedelics and created licensed healing centers. Prop 122 is broader and applies across the whole state.
Denver 301 was just the first move. Check the current rules for your state and see the national map of decriminalization and legalization.
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