The Origins of 4/20

by Raisa Tolchinsky

The article originally appeared on

It’s probably not news to you that 4/20 is often recognized as the national cannabis holiday. Maybe the day is marked on your calendar with a gold star, or maybe you ignore it completely. But how did this holiday come to be, exactly?

People have mused that 4/20 originated from a police code for “Marijuana Smoking in Progress,” the number of active chemicals in cannabis, a refrain from a Bob Dylan song, and even Adolf Hitler’s birthday. But the true origin of 4/20 comes from a group of California teenagers in the early 70s called “The Waldos,” who used to meet up after practice at 4:20 pm on the dot to smoke and scout out a rumoured cannabis crop. According to, the Waldos “learned of a Coast Guard member who had planted a cannabis plant and could no longer tend to the crop.” Using a treasure map supposedly drawn by the plant’s owner, the group would meet outside their high school once a week to search the nearby Point Reyes Forest.

Steve Capper, one of the original members of the Waldos, told the Huffington Post, “We would remind each other in the hallways we were supposed to meet up at 4:20.”

The connection between cannabis and 4/20 spread because of the Waldos connection to The Grateful Dead. One of their father’s managed the Dead’s real estate. Steve explained to the the Huffington Post, “There was a place called Winterland and we’d always be backstage running around or onstage and, of course, we’re using those phrases. When somebody passes a joint or something, ‘Hey, 420.’ So it started spreading through that community."

While the police code is a myth, there is a California State Senate Bill 420 about medical marijuana that references the unofficial holiday (making it feel more like an official one.) But most fascinating about this holiday is how a group of teens infused a sense of ritual and ceremony into cannabis culture, starting a nationwide association between cannabis and 4/20.

And, while it didn’t occur on 4/20 exactly, we might appreciate the discovery of CBD on a day that celebrates all things cannabis. According to, it wasn’t until 1940 that American scientist Roger Adams identified CBD. Twenty years later, Israeli scientist “Raphael Mechoulam described CBD’s chemical structure, and importantly determined that it was non-psychoactive.” Without their work, we wouldn’t know about CBD’s ability to reduce pain, inflammation, anxiety, and its myriad of other benefits.

So this 4/20, celebrate the work of Roger Adams, Raphael Mechoulam, and the healing powers of cannabis… with new knowledge of its origins.


Special thanks to Faye Sakellaridis and her original article and research.