Every year on April 20, cannabis culture centers itself around a single number. "420" shows up as a time, a date, a nickname for cannabis itself, and a full-blown unofficial holiday. Unlike most pieces of drug slang, the origin of "420" is not myth or guesswork — it is one of the few pieces of cannabis folklore with actual documentary evidence behind it, tracing back to five specific teenagers in 1971.
Five Friends Called the Waldos
In the fall of 1971, five students at San Rafael High School in Marin County, California — Steve Capper, Dave Reddix, Jeffrey Noel, Larry Schwartz, and Mark Gravitch — called themselves "the Waldos." The nickname had nothing to do with cannabis; they picked it because they used to hang out by a wall outside the school. They were an ordinary group of friends, not a subculture or a club, which is part of why their story has survived largely intact rather than being reshaped into a bigger legend.
The Treasure Map
That fall, one of the Waldos received a hand-drawn map to a cannabis patch reportedly no longer being tended by a member of the US Coast Guard stationed near Point Reyes. The group agreed to meet after school at 4:20 p.m., by the statue of the chemist Louis Pasteur on the San Rafael High campus, to go search for it. They never found the patch, but they kept meeting at 4:20 to get high and look for it anyway, and started using "420" as shorthand between themselves — first for the meet-up time itself, then more broadly as a private code word for cannabis.
How It Spread: The Grateful Dead Connection
The Waldos had direct ties to the Grateful Dead's circle around Marin County — one of the Waldos' fathers managed real estate for the band, and a Waldo's brother worked as a roadie — and the term moved through that network during the 1970s and 1980s as the group stayed connected to the band's touring scene. From there it spread through Deadhead subculture largely by word of mouth, well before it ever reached the wider public.
How It Went National
The term broke into the mainstream through High Times magazine. A writer covering a Grateful Dead concert in the early 1990s reportedly received a flyer inviting people to smoke "420" at 4:20 on 4/20, and High Times reprinted it, introducing the number to a national readership without yet knowing where it had actually come from. Later in the decade, a High Times editor tracked the term back to the Waldos themselves and published their account, which is what most detailed retellings of 420's history now rely on.
Why This Origin Story Holds Up
What separates this from other pieces of drug slang folklore is that the Waldos kept physical evidence from the time: postmarked letters from the early 1970s referencing "420" in a cannabis context, a school newspaper clipping, and a tie-dyed flag bearing the number, reportedly kept in a safe-deposit box in San Francisco ever since. When the Oxford English Dictionary added "420" as an entry in 2017, its editors cited this kind of preserved, dated material as part of what made the Waldos' account credible enough to document as the term's origin — an unusually well-verified backstory by the standards of drug slang.
Myths That Don't Hold Up
Several competing explanations for "420" have circulated for decades, and none of them have documentary support:
- The police code myth: the claim that 420 was California police radio code for "marijuana smoking in progress" has never been substantiated by any law enforcement agency.
- The Bob Dylan song myth: some point to the lyric "everybody must get stoned" in "Rainy Day Women #12 & 35," noting that 12 multiplied by 35 equals 420. This is a coincidence pointed out after the fact, not a documented source.
- The chemical compound myth: the idea that cannabis contains exactly 420 active chemical compounds is inaccurate; the number of known cannabis compounds has never matched that figure.
The Waldos' account is the version that historians, linguists, and the Oxford English Dictionary itself now treat as the actual origin — a small, specific, well-documented story about five California teenagers and an abandoned cannabis patch they never actually found.