20-5-303. Jurisdiction to modify determination. (a) Except as provided in W.S. 20-5-304, a court of this state may not modify a child custody determination made by a court of another state unless the court of this state has jurisdiction to make an initial determination under W.S. 20-5-301(a)(i) or (ii) and: (i) The court of the other state determines it no longer has exclusive, continuing jurisdiction under a provision of law from that state that is in substantial conformity with W.S. 20-5-302 or that a court of this state would be a more convenient forum under a provision of law from that state that is in substantial conformity with W.S. 20-5-307; or (ii) A court of this state or a court of the other state determines that the child, the child's parents and any person acting as a parent do not presently reside in the other state.
Wyoming Legal Code