Last verified: March 2026

Amendment 64: The Law That Changed the World

Amendment 64 was approved by Colorado voters on November 6, 2012, with 55.32% of the vote. It amended the Colorado Constitution (Article XVIII, Section 16) to legalize the personal use, possession, and home cultivation of cannabis for adults 21 and older. The amendment was framed under the campaign slogan "Regulate Marijuana Like Alcohol" — a messaging strategy led by Mason Tvert, Brian Vicente, and Betty Aldworth that proved devastatingly effective.

Governor John Hickenlooper, who opposed the measure, signed it into law. Implementation moved remarkably fast: a 24-member task force issued 58 regulatory recommendations by March 2013, voters approved the tax structure (Proposition AA) in November 2013, and the first sales began January 1, 2014.

What Is Legal Under Amendment 64

• Purchase: Adults 21+ can buy up to 1 ounce of flower, 8 grams of concentrate, or 800mg of edible THC per transaction from any licensed dispensary.
• Possession: Up to 2 ounces of cannabis or its equivalent outside the home.
• Home cultivation: 6 plants per adult (3 mature/flowering), 12 maximum per household regardless of number of adults.
• Gifting: Up to 1 ounce to another adult 21+, with no remuneration (no sales, trades, or exchanges).
• Consumption: On private property with the property owner's permission, or at a licensed consumption lounge.

What Remains Illegal

• Public consumption: Smoking, vaping, or consuming cannabis in any public space, including sidewalks, parks, trails, concert venues, and restaurant patios.
• Driving under the influence: Colorado's DUI law sets a 5 ng/mL THC permissible inference threshold.
• Federal land: Cannabis is illegal on all federal property, including Rocky Mountain National Park, national forests, and military installations.
• Transport across state lines: Taking cannabis out of Colorado is a federal crime regardless of the destination state's laws.
• Sales without a license: Unlicensed sales are a felony.
• Underage possession: Cannabis is prohibited for anyone under 21.

The Local Option: Why 65% of Towns Opted Out

Amendment 64 includes a local option clause allowing any municipality or county to ban cannabis businesses entirely. As of 2026, roughly 65% of Colorado's 273 municipalities have opted out of recreational sales, and nearly half of the state's 64 counties prohibit all cannabis facilities. Only 25 of 64 counties allow some form of recreational business.

The most notable opt-out was Colorado Springs, the state's second-largest city, which banned recreational sales for over a decade before voters approved Ballot Question 300 in November 2024. Recreational sales began there in April 2025.

The Regulatory Framework

Colorado's cannabis industry is regulated by the Marijuana Enforcement Division (MED) within the Department of Revenue. The MED oversees licensing, compliance, testing requirements, packaging standards, and the Metrc seed-to-sale tracking system. This regulatory model became the template that dozens of states subsequently adapted.

Don't break out the Cheetos or Goldfish too quickly.

Governor John Hickenlooper, upon signing Amendment 64