420 is a code-term that refers to the consumption of cannabis. According to the legend, a group of students in San Rafael, California met at 4:20 p.m. to go in search of an abandoned cannabis grove. From thenceforth forward they used 4:20 to refer to cannabis activity in general. From these humble origins, April 20 has become a counterculture holiday, where people gather to celebrate and consume cannabis.
One of the stranger consequences of the 420 Movement is the theft of traffic and other signs which display the number 420. In Colorado, the Department of Transportation replaced the Mile Marker 420 with one reading 419.99 and in Goodhue County, Minnesota, officials have changed “420 St” street signs to “42x St.”