C.R.S. § 40-10.1-201

(1) A person shall not operate or offer to operate as a common carrier in intrastate commerce without first having obtained from the commission a certificate declaring that the present or future public convenience and necessity requires or will require such operation. (2) The fact that a person carries on operations, in whole or in part, between substantially fixed points or over established routes, or under contracts with more than one person, or by making repeated or periodic trips is prima facie evidence that the person is a common carrier and subject to this part 2 and part 1 of this article.