C.R.S. § 14-13-205

(1) Before a child-custody determination is made under this article, notice and an opportunity to be heard in accordance with the standards of section 14-13-108 must be given to all persons entitled to notice under the law of this state as in child-custody proceedings between residents of this state, any parent whose parental rights have not been previously terminated, and any person having physical custody of the child. (2) This article does not govern the enforceability of a child-custody determination made without notice or an opportunity to be heard. (3) The obligation to join a party and the right to intervene as a party in a child-custody proceeding under this article are governed by the law of this state as in child-custody proceedings between residents of this state.