The History of 420
420 – the number that has become ubiquitously associated with cannabis and marijuana. Every connoisseur of the sticky icky has, at one point, scrambled to light their joint at 4:19 in order to imbibe in time for the psychedelic hour of 4:20. April 20th has become the unofficial stoner Christmas, and the State of California even hilariously passed their infamous Medical Marijuana Program Act under the moniker SB420. 420 shows up regularly in pop culture as well. Next time you watch Tarantino’s classic film Pulp Fiction, pay attention to the clocks. Nearly all of them are set to 420.
But how exactly did it come to pass that 420 would become a symbol for red eyes and smoldering bongs? 
The Mythology
Over the years, creative potheads have concocted numerous stories to explain the omnipresent phenomenon of 420.
Some swear that the number originated as the California police code for marijuana smoking in process. A couple of chuckleheads overheard the number used on a police radio and began co-opting the number. However, the actual 420 police code references obstructing entry on public land.
Others contend that the number originated from a famous Bob Dylan song, Rainy Day Women #12 & 35. During the tune, a croaky Dylan sings out during the refrain, “Everybody must get stoned.” The idea here is that if you multiply 12 by 35, you get 420. I’m sure whoever thought this one up had followed Bob’s advice and was sufficiently stoned at the time of conception. However, this is not the case, either.
Surprisingly, 420’s origin begins not with the police or folk music, but in a San Rafael Califonia, high school.
The True History of 420
Yes, 420 has humble beginnings among lockers, puberty, and interestingly famed chemist Louis Pasteur. The legend goes like this:
A group of student athletes who called themselves The Waldos had come upon the potential for some free Weed. The Waldos got a tip that an older brother in the Coast Guard was no longer able to continue cultivating his secret stash of Mary Jane plants. The boys decided to meet after school by the statue of Louis Pasteur at exactly 4:20 to hunt for the unattended pot plants.
Their first search was unsuccessful, however, they remained undeterred. They resolved to continue the search and would remind each other while walking the halls of their afternoon treasure hunt by saying 420 Louie. Weeks went by, and eventually, they dropped the Louie and shortened the code to the now famous 420.
The Waldos never did find the hidden cache of weed, but they did promptly light up together every day at 4:20. While they eventually gave up the hunt, the term 420 stuck around as an insider code word for marijuana. This may sound a little far-fetched, but The Waldo’s have proof to back up their claims, including numerous post-marked letters circa the 1970s containing 420. 
The Spread of 420
But how did high school slang become a global cultural phenomenon? The answer lies with the iconic stoner jam band The Grateful Dead. After burning out in San Fransico, The Dead picked up and moved to Marin County – only a few blocks away from San Rafael Highschool.
One of The Waldo’s older brothers became close with Grateful Dead bass player Phil Lesh, and the two smoked together on numerous occasions. Another of the Waldos began working as a roadie for the band, and they all hung around backstage during shows. During these hazy pre-show sessions, 420 began expanding from kids code to into what it is today. When The Dead went on tour, 420 came with them, and soon the phrase went nationwide.
When High Times editor Steve Hager got hip to the phrase, it took on an even larger audience. High Time started creating large-scale events referencing 420 that took the term from a cult following of deadheads and transformed it into the quasi-mainstream international symbol that it is today.