Colorado Revised Statutes Title 40. Utilities § 40-20-112. Execution of contract

(a) The contract is acknowledged by the vendee or lessee before some officer authorized by law to take acknowledgments of deeds;

(b) Such instrument is recorded or a copy thereof filed in the office of the secretary of state and in the office of the county clerk and recorder of each of the counties in which the railroad may be operated in this state;

(c) Each locomotive engine or car so sold or contracted to be sold or leased has the name of the vendor or lessor or the assignee of such vendor or lessor plainly placed or marked on each side thereof or otherwise marked so as to indicate the ownership thereof or that the same is covered by such special contract.