The official state code, Oklahoma Statutes, is published under the direction of the Oklahoma Supreme Court Justices. These volumes contain the text of all the state statutes in force, with historical notes following each statute section.
When the people of Oklahoma circumvented the legislature and governor and created statutory laws to enable marijuana to be used in health care, the state supreme court had a duty to codify the initiative petition into the statutes under the 'title 63' public health code.
They had to decide on a numeric code for this law. Ironically, the number 420 was available. Evidently it was too irresistible to the clerical department. the first statute in state history which specifies a lawful use of cannabis is now referred to as a "420" authorization.
Since the 1970s, a '420' has been a code word for a marijuana event. Several theories exist regarding the origin, and the rock group "Grateful Dead" made references to cannabis usage via '420' in their lyrics of the era.
When SQ788 petitioners presented their requisite signatures on August 10th of 2016, Secretary of State, Chris Benge, officially signed the receipt to the group, he had to add the date & time to the official form. When he asked someone to confirm the time, his staffer said; "it's 4:20" (which ironically was the correct time).