A group of people in San Rafael, California,[2][3]calling themselves the Waldos[4] because “their chosen hang-out spot was a wall outside the school”,[5] used the term in connection with a fall 1971 plan to search for an abandoned cannabis crop that they had learned about.[4][6]The Waldos designated the Louis Pasteurstatue on the grounds of San Rafael High School as their meeting place, and 4:20 p.m. as their meeting time.[5] The Waldos referred to this plan with the phrase “4:20 Louis”. Multiple failed attempts to find the crop eventually shortened their phrase to simply “4:20”, which ultimately evolved into a codeword that the teens used to mean marijuana-smoking in general.[6] Mike Edison says that Steve Hager of High Times was responsible for taking the story about the Waldos to “mind-boggling, cult like extremes” and “suppressing” all other stories about the origin of the term.[7]

Hager wrote “Stoner Smart or Stoner Stupid?” in which he called for 4:20 p.m. to be the socially accepted hour of the day to consume cannabis.[8] He attributes the early spread of the phrase to Grateful Dead followers, who were also linked to the city of San Rafael.[8]