Crowds were serenaded by live music as they waited for the nation's first legal recreational pot shops to open. They ate doughnuts and funnel cakes as a glass-blower made smoking pipes. Some tourists even rode around in a limo, eager to try weed but not so eager to be seen buying it.
And when the sales began, those who bought the drug emerged from the stores, receipt held high and carrying sealed shopping bags, to cheers.
"I'm going to frame the receipt when I go home, to remind myself of what might be possible: Legal everywhere," musician James Aaron Ramsey, 28, who did some time in jail for pot possession in Missouri and played folk tunes with his guitar for those in line.
Activists hope he's right, and that the experiment in Colorado will prove to be a better alternative to the costly American-led drug war, produce the kind of revenue that state officials hope and save the government costs in locking up drug offenders.
Just on the first day, prices had already risen to more than $500 an ounce, but it's too soon to say whether that will hold.
Washington state will open its pot industry later this year. Both states programs will be watched closely not just by officials in other states, but by activists and governments in other countries because the industries will be the first to regulate the production and sale of the drug.
Some countries have decriminalized the drug, and the Netherlands lets people buy and sell it, but it's illegal to grow or process it.
Just as shops opened Wednesday, the Denver police department tweeted, "Do you know the law?" and linked to city websites on state and local laws that include bans on public consumption, driving under the influence, taking marijuana out of state and giving pot to anyone under 21.
The Denver police said one person was issued a summons for public consumption. The Colorado State Patrol reported no pot-related incidents. No pot-related incidents were reported at Denver International Airport, where signs warned travelers that they can't take the drug home.
At least 24 pot shops in eight towns opened. In Denver, pot users welcomed the new year and the new industry by firing up bongs and cheering in a cloud of marijuana smoke at a 1920s-themed "Prohibition Is Over" party — a reference to the 1930s-era law that outlawed marijuana.
Shopper Jacob Elliott said he wrote reports in college about the need to end pot prohibition, but never thought it could happen in his lifetime.
"This breaks that barrier," said Elliott, who traveled to Colorado from Leesburg, Va., to be among the first to buy legal weed.
Preparation for the retail market started more than a year ago, soon after Colorado and Washington voters in 2012 approved legal pot industries. Uruguay passed a law in December to become the first nation to regulate pot, but regulatory system isn't in place yet.
Pot advocates, who had long pushed legalization as an alternative to the drug war, had argued it would generate revenue for state coffers — and in Colorado's case to support education — and save money by not locking up low-level drug offenders.
"I feel good about it. The money's going to schools," said shopper Joseph Torres of Denver.
The price for high-quality weed at some shops was around $400. That's about four times what smokers are currently paying on the black market in Colorado, according to crowd-sourced internet surveys. Much of the extra cost was attributed to state and taxes in excess of 25 percent.
Others who were waiting in line shared their own pot incarceration stories over coffee and funnel cakes.
Colorado set up an elaborate plant-tracking system to try to keep the drug away from the black market, and regulators set up packaging, labeling and testing requirements, along with potency limits for edible pot.
The U.S. Justice Department outlined an eight-point slate of priorities for pot regulation, requiring states to keep the drug away from minors, criminal cartels, federal property and other states in order to avoid a federal crackdown.
With the additional police patrols, the airport warnings and various other measures, officials hoped they have enough safeguards in place to avoid predictions of public health and safety harm from the opening of the pot shops.
A group of addiction counselors and physicians said they're seeing more marijuana addiction problems, especially in youths, and that wider pot availability will exacerbate the problem.
"This is just throwing gas on the fire," said Ben Cort of the Colorado Center for Dependency, Addiction & Rehabilitation at the University of Colorado Hospital.
Some medical marijuana patients groups say they're worried about supply. That's because the retail inventory for recreational use is coming entirely from the preexisting medical inventory. Many in the industry warned patients to stock up before the sales began.
It was too soon to tell whether prices were going up.
For now, medical patients should have plenty of places to shop. Most of Colorado's 500 or so medicalmarijuana shops haven't applied to sell recreational pot, and many that have plan to serve both recreational and medical patients
The industry has not just given rise to shops, but a whole line of other businesses, including tours.
Addison Morris, owner of Rocky Mountain Mile High Tours, had 10 clients waiting inside a limo who paid $295 for three hours of chauffeuring by a "marijuana concierge" who would help them choose strains and edible pot products.
Morris said she's booked through the end of February with out-of-state clients, who get samples in designer bags. And for the tours, guests are asked to leave cameras at home. She said she's selling discretion.
"We're your grandmother's pot connection," the 63-year-old said.
Associated Press writer Jim Anderson contributed to this report.