Oft-stolen Colorado mile marker favored by pot smokers gets new number DENVER, Jan. 13 (UPI) -- The Colorado Transportation Department says it replaced an oft-stolen 420 mile marker with one at mile 419.99 to make it less attractive to pot smokers. Department spokeswoman Amy Ford said the 420 sign had been stolen several times, likely due to the number 420 being popular slang for marijuana smoking, so officials decided to replace the marker along Interstate 70, east of Denver, with a less desirable number, KDVR-TV, Denver, reported Monday. Ford said she did not exactly how many times the sign had been stolen.