C.R.S. § 19-4-104
19-4-104. How parent and child relationship established
19-4-104. How parent and child relationship established. The parent and child relationship may be established between a child and the natural mother by proof of her having given birth to the child or by any other proof specified in this article, between a child and the natural father pursuant to the provisions of this article, or between a child and an adoptive parent by proof of adoption.