Colo. Rev. Stat. § 38-43-102
All persons in being having a vested, contingent, or possible interest in the lands or estate or interest sought to be leased shall be made parties to such proceedings, and all persons unknown and all persons not in being, who may have or become entitled to a vested, contingent, or possible interest in such lands, may also be made parties to such proceedings by the general description of unknown persons. Such proceedings shall be in the nature of an action in rem, and the process, practice, and procedure shall be in compliance with the Colorado rules of civil procedure then in effect. The court shall appoint a guardian ad litem to represent any such parties who may be minors or persons of unsound mind, unless they are represented by their statutory guardians or conservators. If the court specifically finds that the welfare or interest of any person not in being requires special representation, the court may appoint a guardian ad litem to represent such unknown party not in being, and such guardian ad litem shall file such pleadings or answer and take such steps as he deems proper, and such unknown person not in being will be fully bound by the proceedings under this article, and same shall be conclusive on any such person. Otherwise, and in the absence of such findings by the court, it shall not be necessary to make parties any persons not in being, but the persons in being who are parties shall stand for and represent the full title and whole interest in said lands, or estate or interest therein, and all parties not in being who might have some contingent or future interest therein, and all persons, whether in being or not in being, having any interest, present, future, or contingent, in the property sought to be leased will be fully bound by the proceedings under this article, and same shall be conclusive on all such persons.
C.R.S. § 38-43-102