'High Holiday' 420 has hazy origins

A farmer puts his marijuana plant into soil
April 20, or 4/20, may be the unofficial holiday for pot smokers, but its origins are particularly hazy. (Image credit: Eric Limon/Shutterstock)

Today is April 20 — or 4/20 for all the marijuana enthusiasts out there. It is the unofficial holiday for people who want to get high all over the world.

The day has become so inextricably linked with the herbal leaf that a Google search lists 420 as simply one of the date's holidays and observances (along with UN Chinese Language Day). But how exactly did the association between 420 and marijuana begin?

The story told on countless couches around the country is that "420" is police code for a marijuana arrest. But take a clear-eyed look at that explanation, and it goes up in smoke.

Related: 25 Odd Facts About Marijuana

Arrest in progress myth

It turns out, the terminology that linked 4/20 with smoking pot took root in Northern California in the early 1970s, said Steve Bloom, the publisher of CelebStoner and the founder of Freedom Leaf magazine.

Bloom, however first came upon the connection when he was given a flier at a Grateful Dead concert at the Oakland-Alameda County Coliseum in 1990. The flier recounted the now-famous apocryphal tale that 420 was police code for a marijuana arrest in progress.

"The makers of the flier thought it was a good idea to turn that around and smoke on 4/20," Bloom told Live Science.

The flier urged its readers to celebrate 4/20 as "the grandmaster of all holidays," when they should meet up with friends to smoke pot together at 4:20 p.m. on 4/20, Bloom said.

Bloom wrote about the flier in High Times magazine, and the idea soon took off, he said.

True origins of 420

But the police-origin story was off the mark, as that is not the code used for a marijuana bust.

"A few years later a few other people got in touch with High Times claiming they were the rightful owners of 420," Bloom said.

It turned out that a group of men who called themselves the Waldos went to high school in San Rafael in California during the 1970s, when the Grateful Dead lived there and the hippie culture reigned supreme. One day they heard a story from a friend about a patch of weed being grown by a U.S. Coast Guard member near the coastal town of Point Reyes. The Coast Guard member was too scared to go harvest it, so the Waldos decided to go on a treasure hunt for the marijuana patch. They decided to meet at a Louis Pasteur statue near campus at 4:20 p.m. to accommodate their school schedules, before heading off in search of the green gold, according to 420Waldos.com, a website set up by the high-school group of friends which now includes information on the holiday's origin.

The pot search routine went on for weeks and the group agreed to meet every day at "420 Louis" to continue the search. Though it wound up being a wild goose chase, it eventually gave rise to the shortened term "420" to denote smoking marijuana.

"We didn't know we were creating history at the time, it was just a private joke we were telling between ourselves," said Dave Reddix, one of the original waldos, who is now an independent filmmaker in San Francisco.

The Grateful Dead lived in San Rafael at the same time as the Waldos, and the group sometimes hung out in "deadhead" circles, even lingering backstage after shows. Gradually, their terminology spread through the Grateful Dead community into the wider stoner culture, Bloom said. 

The Waldos not only spoke with an editor at High Times (not Bloom) and signed statements attesting the truth of their story, but they also provided documents, such as old letters referring to marijuana by its numerical nickname, old high-school newspapers using the term, and even a "420," batik-dyed marijuana flag, according to 420Waldos.com. Though they were initially anonymous, but in the late 1990s, a few of the original group have come forward with their real names. Recently, they even found the U.S. Coast Guard member, who is now homeless, and finally found the location of the original pot, Reddix said.

Wider cultural trend

many people and vans outside large arena in Oakland

People wait outside a Grateful Dead concert at the Oakland Arena on Dec. 12, 1992. Bloom first found a flyer describing the holiday "420" as a police arrest in progress at such a concert, but that urban myth had been circulating at least 15 years prior to the concert. (Image credit: Tim Mosenfelder/Getty)

But how exactly did the term make its way from a local term to a global holiday? The flier that Bloom and others received at the Oakland Grateful Dead concert may have been the catalyst that launched "420" from local Northern California underground slang to the central day for major marijuana celebrations and protests throughout the world.   But the false association between police busts and 420 predates the Grateful Dead concert by at least 15 years, said Steve Capper, one of the Waldos, who is now in the financial services industry in San Francisco.

"The first time I heard it, I was going to school in Southern California," somewhere between 1974 to 1975, Capper told Live Science. "I'd fly back and would pass by a high-school kid hitchhiking."

After picking them up, he would ask them if they knew what 420 was.

"They'd say 'it's a police code for marijuana,'" Capper said.

The real turning point, however, was the Oakland concert, Bloom said.

"I was not the only person who got the flier, but was the one who was able to spread it out through the magazine," Bloom said. "Over the years, it just kind of picked up steam. That was really what started to build up the 4/20 phenomenon."

Exactly who created the flier, and launched 4/20 into a global day of celebration of all things cannabis, however, is still unknown.  

"The mysterious deadheads behind the flier are the ones who created the holiday," Bloom said. "It's become the stoner high holiday, and these guys are the people who created it."

Editor's Note: This article was originally published in 2017 and updated April 20, 2023.

Tia Ghose
Managing Editor

Tia is the managing editor and was previously a senior writer for Live Science. Her work has appeared in Scientific American, Wired.com and other outlets. She holds a master's degree in bioengineering from the University of Washington, a graduate certificate in science writing from UC Santa Cruz and a bachelor's degree in mechanical engineering from the University of Texas at Austin. Tia was part of a team at the Milwaukee Journal Sentinel that published the Empty Cradles series on preterm births, which won multiple awards, including the 2012 Casey Medal for Meritorious Journalism.