Ask ten people where 420 comes from and you may get ten different answers. Police radio code. The number of chemicals in cannabis. A famous birthday. A Bob Dylan song. The real story is smaller and stranger than any of those. It starts with a group of high school friends in Northern California in 1971, a treasure map and a meeting time after class. From there, a band, a magazine and decades of word of mouth turned a private joke into a worldwide shorthand. Here is how it happened.

The Waldos of San Rafael

In the fall of 1971, a group of students at San Rafael High School in Marin County, California, called themselves the Waldos. The name came from the wall they liked to hang out on outside school. The group had about five core members, and they were known for chasing adventures and pranks.

According to the Waldos, one of them came across a hand drawn map that supposedly showed where a member of the Coast Guard had planted a cannabis patch near the Point Reyes Peninsula and could no longer tend it. The friends decided to go find it.

Why 4:20

The Waldos agreed to meet at 4:20 in the afternoon by a statue of the scientist Louis Pasteur on the school grounds. That time worked because sports practice had ended and they could slip away together. The reminder in the hallways became a quick phrase: 420 Louis. Over time they dropped Louis and just said 420.

They searched the Point Reyes area several times and never found the crop. But the code word stuck. It became a private way to talk about cannabis in front of parents and teachers without being obvious.

How a local joke went global

A private phrase among five friends could easily have faded out. Two things kept it alive.

The Grateful Dead connection. The Waldos had ties to the Grateful Dead scene. One member’s father managed real estate for the band, and another member’s brother was friends with bassist Phil Lesh. The Waldos hung around rehearsals and shows, and the phrase spread among the band’s huge, traveling community of fans through the 1970s and 1980s.

The 1990 flyer. In December 1990, Deadheads in Oakland handed out flyers inviting people to gather at 4:20 pm on April 20. A copy reached a reporter at High Times, which printed it in 1991. From there the magazine kept using the number, and 420 became part of the national cannabis vocabulary.

How we know this story

What sets the Waldos account apart from rival theories is evidence. Members kept items from the early 1970s, including a dated letter and a flag with the number on it, and they have described the story consistently for decades. Journalists who looked into the origin, including writers at High Times and mainstream outlets, have generally pointed to the Waldos as the most credible source. Some details, like exactly who first said it, may never be fully settled, but the overall timeline holds up better than any other explanation.

Myths about 420

Many alternative stories still get passed around. Here is how they stack up.

Myth	Reality
420 is a police code for cannabis use	No police department has been shown to use 420 this way
Cannabis contains exactly 420 chemical compounds	The count varies by source and does not land on 420 as a fixed number
It marks a famous person’s birthday	Coincidence, unrelated to the origin
It comes from a Bob Dylan song	Fun math trivia, but there is no evidence it inspired the phrase
April 20 was chosen first	The time came first, the date followed later

From code word to cultural holiday

By the 2000s, April 20 had become a day for rallies, concerts and gatherings in cities across North America. Activists used the date to push for legalization. As states legalized adult use, 420 also became a big retail day, with sales and events in legal markets.

The number shows up in surprising places too. Highway signs with mile marker 420 have been stolen so often that some states replaced them with 419.99. Hotels and rentals use 420 friendly as shorthand for whether cannabis is allowed, a phrase we break down in our post on what 420 friendly means.

Why the story still matters

The 420 story is a reminder of how culture works. It did not start with a company, a campaign or a law. It started with friends, a shared joke and a community that liked passing things along. Knowing the real history also helps cut through the myths that still float around online. If you want the broader timeline of how cannabis laws changed over the decades, read our history of recreational cannabis before and after strict laws.

Celebrating 420 today

For adults 21 and older in legal states, 420 is a chance to enjoy the culture responsibly. Some people host small gatherings, some visit legal events and some simply spend the day in the garden. If you grow your own, April is a good time to plan an outdoor season, start seeds indoors or tend a spring garden where home growing is legal. Our guide on how to germinate cannabis seeds is a good place to start.

A quick 420 timeline

• 1971: the Waldos meet at 4:20 pm at San Rafael High School to search for the Point Reyes crop.
• 1970s and 1980s: the phrase spreads through the Grateful Dead community.
• 1990: Deadheads in Oakland hand out a flyer calling for a 4:20 gathering on April 20.
• 1991: High Times prints the flyer and starts using the number regularly.
• 2000s: April 20 rallies grow in major cities.
• 2010s and beyond: legal states turn 420 into a major retail and event day.

Each step added a new audience, and together they turned a school hallway joke into one of the most recognized numbers in the world.

Enjoy cannabis culture responsibly

Cannabis is only legal for adults in some states, and the rules on possession, public use and home growing change from place to place. Kind Seed Co sells only to adults 21 and older, and nothing here is an invitation to break the law where you live. If you want to know what is allowed in your state, start with our guide to the legal requirements for growing weed plants in your state. Never drive after using cannabis, keep it away from kids and pets, and respect anyone who chooses not to partake. This article is general information about culture and history. It is not legal advice and it is not medical advice.

Frequently asked questions

What does 420 really mean?

420 started as a code word used by a group of San Rafael High School students in 1971 who met at 4:20 pm to search for a hidden cannabis patch. It became shorthand for cannabis in general.

Who started 420?

A group of friends known as the Waldos at San Rafael High School in California. Their account is backed by dated items from the early 1970s.

Is 420 a police code?

No. That is a popular myth with no evidence behind it.

Why is April 20 called 420 day?

The time came first. Later, fans and activists began using April 20, written 4/20, as a day to gather, and it grew into an annual cannabis holiday.

Final thoughts

The real story behind 420 is a small one that grew huge. Five friends in Marin County picked a meeting time to hunt for a lost cannabis crop, never found it and turned the time into a code word. The Grateful Dead scene spread it, a 1990 flyer and High Times made it national, and decades of culture made it global. Next time someone tells you it is a police code, you will know better.

Ready to start

Browse the full range in the Kind Seed Co shop or go straight to 420 seeds. Kind Seed Co sells only to adults 21 and older. Always follow the cannabis laws where you live.