C.R.S. § 38-20-103

All contracts, or copies thereof, made by the owner of any pet animal with any other person, including a feeder, for the caring for the same for pay, or on shares, or in any other manner may be filed with the county clerk and recorder of the county where the owners or either of them reside, if they reside in the state, and, if the owners or either of them do not reside in the state, the copies may be filed with the county clerk and recorder of the county in which the contract was made. When such copies are so filed they shall be notice to everyone of the contents of such contracts and of the legal effect thereof.