Open and Public While it is legal in the State of Colorado for an adult 21 years of age or older to possess and consume small amounts of cannabis, or a person 18 years of age with a medical cannabis card to possess Published 10 years ago on December 5, 2013 By Ann Toney Related Topics: Continue Reading You may like Click to comment Leave a Reply Cancel replyYour email address will not be published. Required fields are marked *Comment * Name * Email * Website Save my name, email, and website in this browser for the next time I comment.