What’s the real origin of 420?

From the clock in Ted and Marshall's apartment in How I Met Your Mother to the dials in the pawn store in Pulp Fiction, the number of references to 420 in films and series shows that it has become a symbol of the counterculture around cannabis. 

A trend that goes as far as causing some pretty amazing situations, with many stoners who don’t hesitate to steal traffic signs bearing the three numbers as trophies of their accomplishments. Okay, when you put it that way it's very funny. But eventually, some jurisdictions like the State of Colorado got tired, and decided to replace the stolen signs with ones bearing the number 419.99, to avoid any temptation ... 

Others took the decision to acknowledge this private joke, like the Californian Senate, which passed a law to regulate the use of medicinal cannabis, called "California Senate Bill 420" ... 

Far from Lovecraft's stories or the American police files, the true origin of 420 is attributed to five high school students from San Rafael, California: Steve Capper, Dave Reddix, Jeffrey Noel, Larry Schwartz and Mark Gravich. Their nickname? The Waldos, because they used to lean against a wall after school. 

One day in the fall of 1971, the Waldos heard about Garry Newman, a Coast Guard who was growing marijuana near the Coast Guard Station of the Point Reyes Peninsula. But as time went by, Newman became afraid of being caught by his superiors and decided to abandon his harvest. So he drew a map for those who might want to help themselves along the way. 

The boys immediately get their hands on the map to start looking for the abandoned hemp. They agree to meet every day at 4:20 under the statue of Louis Pasteur to go on a treasure hunt. In order to talk about their plans without anyone else understanding, the Waldos used to call out to each other in the hallways saying "420 Louis!"  

Despite several attempts, the boys would never find the cannabis. The "420", however, stuck, and soon became a code name to refer to their favorite plant. Interviewed by the San Francisco Chronicle, Steve Capper declared “It was just a joke, but it came to mean all kinds of things, like 'Do you have any?' or 'Do I look stoned?’ (...) Parents and teachers wouldn't know what we were talking about.”

Among the theories about the origin of 420, there is also the one statinng that the term "420" was coined by fans of the Grateful Dead rock band, who are known to be heavy consumers, or even by the Dead themselves. 

But when you dig a little deeper, you realize that this theory is directly related to the history of the Waldos, because, as surprising as it may seem, all five boys hung out with the band.

At the same time that the Waldos were searching for their abandoned crop, Grateful Dead decided to establish themselves in the Marin County hills, just a few blocks from San Rafael High School. According to Steve, "Marin Country was kind of ground zero for the counterculture”. 

But the geographical proximity between the Waldos and the rockers doesn't end there. Mark Gravich's father briefly worked with them, not to mention Dave Reddix's older brother Patrick, who was very close to Phil Lesh, the band's bassist. In addition to being his friend and smoking cannabis with him, Patrick managed other bands that Lesh was a part of in addition to the Dead. Dave Reddix himself would later become a roadie for the bassist. 

While he doesn't remember exactly, Patrick said it was most likely that he used the code name coined by his brother and friends in front of Lesh. For his part, the bassist can't remember the first time he heard the term, but said he wouldn't be at all surprised if it came from the Waldos. 

Because before making professional connections, the boys started hanging out on Front Street, where the band was rehearsing. They often met up to smoke and play music. As Dave points out, “we used to go hang out and listen to them play music and get high while they're practicing for gigs. But I think it's possible my brother Patrick might have spread it through Phil Lesh. And me, too, because I was hanging out with Lesh and his band [as a roadie] when they were doing a summer tour my brother was managing”