The warm Boulder air was thicker with the "atom bomb" of marijuana smoke than anticipation as cries of stoned joy mingled with the bluish haze rising among the still-skeletal tree limbs as the 4:20 p.m. hour approached.

Disregarding an e-mail from the CU-Boulder administration pleading with students to forgo this year's 4/20 celebration, roughly 10,000 people gathered on the green lawn of CU-Boulder's Norlin Quad Monday to celebrate what stoners across the nation recognize as something of a national marijuana smoking holiday.

Some on the field claimed to have gathered to push for marijuana legalization, some to flaunt their illegal recreation choices under the nose of the law, some to enjoy the celebration, some to sell their pot printed paraphernalia and some to just revel in a THC-induced delirium.

"Why are we here?" Laura Kriho, a proponent of marijuana legalization yelled to the crowd after taking a mock hit on a giant stuffed joint.

"We're here cause we like to smoke pot!" she yelled in answer to her own question. "It's an annual holiday, and there's not even that many long-haired hippie people."

Sure enough, men and women; students and elderly; people of all creeds, cultures and backgrounds; and even some long-haired hippie people turned out to do just that: smoke some pot.

The city of Boulder has become something of a stoner Mecca in the last decade, its massive 4/20 celebrations drawing crowds from across the state and even nation.

One CU-Boulder student who identified herself as Silvia Plath, said she was hesitant to tie drug-use to Boulder culture, but said she thinks the city definitely benefits from all the merchandise sales.

However, Mike, another student who declined to give his last name, said marijuana smoking is an integral part of Boulder's culture and reputation.

"Boulder is one of the main towns," Mike said about 4/20 celebrations while puffing a marijuana cigar. "People come to Boulder for the weed city."

Gray-haired Steve Bell and his fellow homeless companions Carol Seacrest and Joey David Lee hitchhiked from Louisiana to attend Bell's 30th high school reunion in Loveland, but decided to stop by Boulder on the way for their first 4/20 celebration.

Bell said the truck driver they hitched a ride with asked whether they wanted to get dropped off in Loveland or travel through to Boulder.

"Carol said 'I need some culture,'" Bell said. "I said, 'Boulder.'"

"This is an American festival," Lee said.