DENVER (AP) -- Once the province of activists and stoners, the traditional pot holiday of April 20 has gone mainstream in the first state in the nation to legalize recreational marijuana.
Tens of thousands gathered for a weekend of Colorado cannabis-themed festivals and entertainment, from a marijuana industry expo called the Cannabis Cup at a trade center north of downtown to 4/20-themed concerts at the legendary Red Rocks Amphitheater -- acts include Slightly Stoopid and Snoop Dogg -- to a massive festival at Civic Center Park, in the shadow of the state capitol, where clouds of cannabis smoke are expected to waft at 4:20 p.m. MDT Sunday.
The smokeout is planned despite public consumption of marijuana remaining illegal in Colorado.
Festivities got off to a slow start on Sunday. At noon, as bells from the Catholic cathedral a few blocks away rang out over downtown to signal the end of Easter services, only a few hundred people milled around Civic Center Park. The smell of marijuana was detectable, but mild.
The Civic Center Park event is the most visible sign of the pot holiday's transformation. It started as a defiant gathering of marijuana activists, but this year the event has an official city permit, is organized by an events management company and featured booths selling funnel cakes and Greek food next to kiosks hawking hemp lollipops and glass pipes.
Gavin Beldt, one of the organizers, said in a statement that the event is now a "celebration of legal status for its use in Colorado and our launch of an exciting new experience for those attending. "
Denver is just one of many cities across the country where 4/20 marijuana celebrations are planned Sunday.
In Trenton, N.J., speakers urged a crowd of about 150 gathered at the statehouse to push state and federal lawmakers to legalize or decriminalize marijuana and called on Gov. Chris Christie to do what he can to help medical marijuana patients.
In San Francisco, Police Chief Greg Suhr said his officers would be cracking down on illegal parking, camping, drug sales, underage drinking and open alcohol containers at Golden Gate Park's Hippie Hill. Officials don't want the unofficial pot holiday to disrupt Easter Sunday activities in the park.
In Washington, thousands celebrated in the only other state to legalize marijuana. Events included a Snoop Dogg show Saturday night as well as an event sponsored by Seattle's Dope Magazine, with a $99 "judge's pass" available that included 10 marijuana samples.
Back in Colorado, University of Colorado officials closed the Boulder campus to all but students, faculty and staff on Sunday to ensure no 4/20 celebrations were held. Spokesman Ryan Huff said the tactic was working, with no arrests reported Sunday. The university says marking 4/20 is contrary to its mission of research, teaching and learning, and in the past, it has seeded a main lawn with fertilizer to keep revelers away.
While the weekend was for celebrating, recent events have brought serious scrutiny to Colorado's experiment with legalizing marijuana. Denver police say a man ate marijuana-infused candy before shooting and killing his wife on Monday, an attack dispatchers heard during a 911 call the woman had placed. Her death followed that of a college student who traveled to Colorado with friends from Wyoming for spring break, ate more than the recommended dose of a marijuana-laced cookie, and jumped to his death from a hotel balcony in Denver. State lawmakers are debating how to increase safety regulations.
On Saturday, the first day of a two-day festival in Denver, only a few people lingered on the steps of a Roman-style amphitheater where marijuana activists spoke angrily about bans on the drug in other states. Thousands instead lingered on the park's broad lawns, listening to hip-hop music blasting from the sound stage and enjoying the fresh, albeit marijuana-scented, air.
"It's a lot mellower this year," said Cody Andrews, 29, of Denver. "It's more of a venue now. More vendor-y."
Last year's event was marred by an unsolved shooting that wounded three. This year a fence rings the park. Security guards in protective gear roam the grounds, and all entrants are being checked for weapons.
Denver police said Sunday that they had issued 21 citations for public consumption of marijuana and arrested one person accused of attempting to distribute the drug on Saturday, and issued another seven citations Sunday. Marijuana sales are regulated in the state.
Plenty of participants didn't waiting until 4/20 proper to light up despite public consumption of marijuana remaining illegal. On Saturday, Jairin Genung, 25, of Aurora, sat on the grass with friends, including one who was carefully rolling a thick joint.
"We're going to light up no matter what," Genung said. "If you can't smoke at the 4/20 rally, it just doesn't make sense."
The whole scene was wonderfully surreal for Bud Long, 49, from Kalamazoo, Mich., who recalled taking part in his first 4/20 protest in 1984.
"Nationwide, it'll be decriminalized," he predicted, "and we'll be doing this in every state."
Associated Press writers Terry Chea in San Francisco, Bruce Shipkowski in Trenton, N.J., and Gene Johnson in Seattle contributed to this report.
Follow Nicholas Riccardi on Twitter at https://twitter.com/NickRiccardi.