It starts with the Dead.

It was Christmas week in Oakland, 1990. Steven Bloom was wandering through The Lot – that timeless gathering of hippies that springs up in the parking lot before every Grateful Dead concert – when a Deadhead handed him a yellow flyer.

"We are going to meet at 4:20 on 4/20 for 420-ing in Marin County at the Bolinas Ridge sunset spot on Mt. Tamalpais," reads the message, which Bloom dug up and forwarded to the Huffington Post. Bloom, then a reporter for High Times magazine and now the publisher of CelebStoner.com and co-author of Pot Culture, had never heard of "420-ing" before.

The flyer came complete with a 420 back story: "420 started somewhere in San Rafael, California in the late ’70s. It started as the police code for Marijuana Smoking in Progress. After local heads heard of the police call, they started using the expression 420 when referring to herb – Let’s Go 420, dude!"

Bloom reported his find in the May 1991 issue of High Times, which the magazine found in its archives and provided to the Huffington Post. The story, though, was only partially right.

It had nothing to do with a police code — though the San Rafael part was dead on. Indeed, a group of five San Rafael High School friends known as the Waldos – by virtue of their chosen hang-out spot, a wall outside the school – coined the term in 1971. The Huffington Post spoke with Waldo Steve, Waldo Dave and Dave’s older brother, Patrick, and confirmed their full names and identities, which they asked to keep secret for professional reasons. (Pot is still, after all, illegal.)

The Waldos never envisioned that pot smokers the world over would celebrate each April 20th as a result of their foray into the Point Reyes forest. The day has managed to become something of a national holiday in the face of official condemnation. This year’s celebration will be no different. Officials at the University of Colorado at Boulder and University of California, Santa Cruz, which boast two of the biggest smoke outs, are pushing back. "As another April 20 approaches, we are faced with concerns from students, parents, alumni, Regents, and community members about a repeat of last year’s 4/20 ‘event,’" wrote Boulder’s chancellor in a letter to students. "On April 20, 2009, we hope that you will choose not to participate in unlawful activity that debases the reputation of your University and degree, and will encourage your fellow Buffs to act with pride and remember who they really are."

But the Cheshire cat is out of the bag. Students and locals will show up at round four, light up at 4:20 and be gone shortly thereafter. No bands, no speakers, no chants. Just a bunch of people getting together and getting stoned.

The code often creeps into popular culture and mainstream settings. All of the clocks in Pulp Fiction, for instance, are set to 4:20. In 2003, when the California legislature codified the medical marijuana law voters had approved, the bill was named SB420.

more @ http://www.huffingtonpost.com/2010/04/20/420-meaning-the-true-stor_n_543854.html