This week, Colorado replaced mile marker 420 after it was repeatedly stolen following the state's legalization of marijuana. Why? Could be because 420 is pop-culture code for cannabis.
The Colorado Department of Transportation assumed it was being lifted by "weed enthusiasts," according to NBC News.
To combat further theft, the department altered the sign to "MILE 419.99."
The reasons behind 420's association with pot are relatively unknown, short of a few theories involving 1970s California hippie kids. But April 20 (4/20) has become something of counterculture holiday for the aforementioned enthusiasts.
Amy Ford, a spokeswoman with the Colorado Department of Transportation, told USA Today that, in part, "it's a traffic safety thing. It's a helpful thing to have these signs on the road. But people kept ripping them off."
This isn't Colorado's first attempt at thwarting mile-marker thieves. The Associated Press reports that Cameron Pass in Larimer County also has a fractional sign that reads, "MILE 68.5" after frequent thefts of the "MILE 69" marker.