Wyo. Stat. § 2-9-201
When more than two (2) years have elapsed since the death of a person residing in this state, or residing outside of this state but owning real estate or any interest therein situated within this state, or who has made entry on any government lands and has not received patent therefor, and there has been no previous, record judicial determination of the decedent's heirs or the right of descent of the real property interest, any heir of the deceased or other person having derived title to any real property or any interest therein from the deceased or from any of his heirs either by direct or mesne conveyances, may make application by petition to the court or commissioner of the county in which the deceased was a resident at the time of his death, or if a nonresident of the state at the time of his death then in the district court of the county where the real estate or some part thereof belonging to the deceased in his lifetime is situated, for determination of the time of death of the decedent and a determination of the heirs of the deceased, the degree of kinship and the right of descent of the real property belonging to the deceased.
W.S. 2-9-201