"The Waldos," a group of San Rafael High School students who said they coined the marijuana term '420' in 1971. (CBS)

SAN RAFAEL (KPIX 5) – On Monday, marijuana aficionados marked 420 Day. The term, now famous around the world, was coined right here in the Bay Area.

420 has become the catch all for all things marijuana. It is not the police code for illegal pot, despite what many people believe. April 20th is Adolf Hitler’s birthday, but that has nothing to do with it.

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The phrase known around the globe started here at San Rafael High in 1971 with a group of now decidedly grown up, former stoners. They gathered on this 4-20 to explain the story for KPIX5.

“It was a joke back in the 70s. And we still think it’s a joke,” said Dave Reddix.

Somebody had a map to what they thought was a pot grove. So for weeks they went looking for it. They’d meet up at 4:20 in the afternoon at the Louis Pasteur statue on campus. 4:20 became their code for marijuana.

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They needed code, especially Jeff Noel. His father was a state narcotics officer.

“Of course he was aware, and he was always concerned what we were up to. He had his inklings. He knew. That’s why code was so important,” Noel told KPIX 5.

The code spread. It helped that the group had ties to the Grateful Dead, also Marinites, and the rock band also helped popularize it. It was cemented when High Times magazine documented the story in the late 90s.

“We were calling each other, laughing, about the different 420s that people were coming up with, so we just kind of want to set the record straight as to how it started,” said Larry Schwartz.

They called themselves the Waldos because they used to hang out at a wall on campus. Yes, they still occasionally smoke pot, and no, they have never capitalized on it. But they look at what it’s become and can’t believe it.

“It’s been going on for decades,” said Steve Capper. “At this point, it’s like Baby Boomers getting older, it’s like, they’ll be asking their doctor, ‘Ask your doctor if 420 Day is right for you!’”

And it’s hard for them to comprehend it all started with their unsuccessful treasure hunt, 44 years ago.