Every year on April 20th, cannabis enthusiasts around the world come together to celebrate “420,” a holiday that has grown from underground roots into a symbol of cannabis culture, advocacy, and community. But how did a simple number—420—become synonymous with weed? The origins of 420 are as intriguing as the culture it represents, blending myth, fact, and a little stoner ingenuity.

The True Origin: The Waldos of San Rafael

The most widely accepted origin of 420 traces back to a group of high school friends in San Rafael, California, in the early 1970s. Calling themselves “The Waldos,” these five students would meet after school at 4:20 p.m. to search for an abandoned patch of cannabis rumored to be growing near Point Reyes. They chose the time because extracurricular activities had ended, and they were free to embark on their quest.

Their meeting spot was the statue of Louis Pasteur on their school campus, and the code they used for their cannabis scavenger hunt? “420 Louis.” Eventually, it was shortened to simply “420.”

Though they never found the elusive crop, the term stuck—used as a casual code among friends for anything weed-related.

The Grateful Dead Connection

The spread of “420” from a local high school code to a national phenomenon is thanks, in part, to the Grateful Dead. Several of The Waldos had connections to the band—one of the Waldos’ brothers managed a Dead side project, and another’s father handled real estate for the band. The teens had access to the band’s inner circle and would hang around backstage.

As the Dead toured and their fanbase grew, so did the use of “420.” It became part of Deadhead culture, and the term traveled far beyond the Bay Area.

From Underground to Mainstream

The first documented use of 420 in print was in High Times magazine in the early 1990s. The publication embraced and promoted the term, helping it catch fire across the cannabis community. High Times even helped organize the first public 4/20 events, where people gathered to smoke in solidarity and protest cannabis prohibition.

Since then, 4/20 (April 20th) has evolved into an unofficial holiday for cannabis users around the world. It’s a day of peaceful protest, community gathering, and celebration of cannabis culture—often marked by festivals, concerts, and political rallies pushing for legalization and reform.

Modern 420: A Symbol of Legalization and Culture

As cannabis laws continue to shift in the United States and beyond, 420 has taken on new meaning. It’s no longer just about lighting up—though that still happens in abundance—it’s about reflecting on the journey of cannabis legalization, the people who have fought (and continue to fight) for it, and the industry growing up around it.

Brands now host sales, dispensaries organize parties, and activists use the day to draw attention to social justice issues like expungement of nonviolent cannabis convictions and equitable access to the legal market.

Conclusion: More Than Just a Number

What started as a high school code has become a global cultural touchstone. 420 is more than just a time to toke—it’s a reminder of how grassroots culture, youthful rebellion, and shared language can spark a worldwide movement.

So whether you’re lighting up, learning about cannabis reform, or simply enjoying the vibe, take a moment on April 20th to appreciate the quirky, rebellious, and meaningful history behind 420.