Where Did 420 Come From? The Real Origin of 4/20

By James Buddsey · Updated October 16, 2026

420 comes from a group of five San Rafael High School students in Marin County, California, who called themselves the Waldos and, in the fall of 1971, met at 4:20 p.m. by a statue of Louis Pasteur to smoke and hunt for an abandoned cannabis patch. “420” became their code word, spread through the Grateful Dead scene, and went national after High Times printed a 4/20 flyer in 1991. It is not a police code, a California statute or the number of chemicals in cannabis.

Every April someone repeats one of the myths. The real story is better documented than most cannabis folklore, because the Waldos kept evidence and journalists have checked it. Here is what is known, what is disputed, and how a teenage in-joke became the biggest date on the cannabis calendar.

420 Origin at a Glance

The Waldos and the Treasure Map

The five Waldos were Steve Capper, Dave Reddix, Jeffrey Noel, Larry Schwartz and Mark Gravich, as Time reported.

According to the group’s own account on 420waldos.com, in the fall of 1971 Steve Capper was given a hand-drawn map to a cannabis patch on the Point Reyes Peninsula, north of San Francisco. The plants belonged to a member of the U.S. Coast Guard who was worried about getting caught and was willing to let someone else harvest them. The Waldos agreed to meet after sports practice at 4:20 p.m. at the campus statue of the chemist Louis Pasteur, get high, and drive out to search.

The reminder in the hallways was “4:20 Louis.” They went looking several times and never found the patch. The phrase outlived the hunt: it shortened to “420” and became their code for smoking, something they could say in front of parents and teachers without giving anything away.

How 420 Spread: The Grateful Dead Connection

A private joke in Marin County went worldwide because of who the Waldos knew. Reddix’s brother helped him get work as a roadie for Grateful Dead bassist Phil Lesh, Time reported. “420” caught on backstage and then among Deadheads, who carried it from show to show across the country through the 1970s and 1980s. High Times writer Steven Hager later credited Grateful Dead followers with the phrase’s early spread, according to the Wikipedia summary of 420 culture.

The step from subculture to mainstream came on December 28, 1990. Deadheads in Oakland handed out flyers inviting people to smoke at 4:20 p.m. on April 20. High Times reporter Steve Bloom picked one up, and the magazine published it in 1991. With the leading cannabis magazine using the term, it was soon everywhere. In 1998 High Times acknowledged the Waldos as the originators.

What Proof Do the Waldos Have?

The Waldos say they hold multiple pieces of physical evidence from the early 1970s and that news organizations have verified it. Their claim was investigated and accepted by High Times and has been reported by Time, SFGATE and the Huffington Post, whose reporting in 2009 and 2010 helped bring the story to a mass audience.

There is a rival claim. A separate group of San Rafael teenagers led by Brad Bann, who went by “the Bebe,” says they used “420” first. Adweek covered the dispute in 2012, and SFGATE called the origin “full of controversy” in 2023. Either way, the term was born at the same school in the same era. The Waldos’ version is the one with documentation and the one most historians of the term accept.

420 Myths That Are False

• A police radio code. There is no standard police code 420 for marijuana. The idea appears to come from a May 1991 High Times item that got it wrong, according to the sources collected on Wikipedia.
• The California penal code. California Penal Code section 420 deals with obstructing entry on public land, not cannabis. The cannabis-related “420” in California law is Senate Bill 420, the 2003 medical marijuana law, which shares the number but came decades after 1971.
• The number of chemicals in cannabis. Cannabis contains hundreds of compounds, and the count depends on how you define and measure them. No count explains the term.
• Hitler’s birthday. Adolf Hitler was born on April 20, 1889, but that is a coincidence. The original 420 was a time of day, not a date.
• Bob Dylan’s “Rainy Day Women #12 & 35.” Twelve times 35 equals 420, which is fun, and also meaningless. Nobody involved has ever connected the song to the term.
• Tea time in Amsterdam, a Grateful Dead hotel room, or Jim Morrison’s death. All popular, none supported by evidence.

How 4/20 Became a Holiday

Once High Times promoted April 20, the date took on a life of its own. Large public smoke-outs grew up at Hippie Hill in San Francisco’s Golden Gate Park and on the University of Colorado campus in Boulder, where a 2008 gathering drew an estimated 10,000 people, according to the Boulder Daily Camera. Highway departments learned the cost of the number too: Colorado swapped its constantly stolen Mile Marker 420 sign on Interstate 70 for one reading 419.99 in 2014, USA Today reported.

In legal states 4/20 is now a retail event, with dispensary sales, events and discounts. If you are celebrating in the Northwest, the usual rules apply: buy from licensed stores, keep within purchase limits and do not smoke in public. Our guides to Washington marijuana laws and Oregon marijuana laws cover the details, and our Washington and Oregon dispensary directories will help you find a shop. For the longer story of how cannabis went from colonial crop to prohibited drug and back, read our history of marijuana in America.

420 Origin FAQ

For adults 21+ in legal states. General information, not legal or medical advice.