IIRC Colorado basically follows Fed law on them.....I think you can carry if on duty and carrying out govt duties, emergency response and active military on duty stuff like that. Or if you only have one hand...that's in the fed wording iirc. I'm no lawyer and that isn't legal advice, there are several sites dedicated to the subject of automatic knife legalities state by state. I'd think that just to collect them, who is ever going to know what you have in your house or really care - but federal law really restricts sales across state lines and who can order them so you'll likely be paying a premium at a show or on the street for one (or I hear there are guys who will mail you one, but I think that would be questionable). Watch out for fakes, idk about Benchmade but when I bought my Microtech I contacted them to verify it's authenticity (contacted them and one of the production managers had me email pics and the serial number).