C.R.S. § 18-13-120

(1) As used in this section, “drip gasoline” means a combustible hydrocarbon liquid formed as a product of condensation from either associated or nonassociated natural or casing-head gas which remains a liquid at the existing atmospheric temperature and pressure. (2) Every person, other than a producer, refiner, pipeline company, or owner or operator of a natural gas processing plant or their authorized agents, who transports or stores drip gasoline in this state shall have in his possession a written instrument issued and signed by a licensed seller of gasoline, stating the names and addresses of the seller and purchaser, the date of sale, and the amount sold and paid for such drip gasoline, or a copy of a contract authorizing the loading and transportation of the drip gasoline. (3) The use of drip gasoline in a motor vehicle operated on the highways of this state is prohibited. (4) Any person who violates subsection (2) or (3) of this section commits a petty offense.