The western state, one of three voting on the measure, voted by 52.7% in favour to 47.3% against, according to the Denver Post, with over 50% of votes counted. CNN gave 53% for with 47% against.
A number of US states have legalised the use of marijuana for medicinal purposes, but Colorado, Oregon and Washington state all voted on Tuesday on legalising recreational use as well.
In Washington state 55% of voters backed the move, with 45% against, according to CNN and NBC, citing figures with 50% of votes counted.
In Oregon voters appeared set to reject the proposal, with 55% against and 45% in favour, according to CNN, with 47% of votes counted. – Sapa