Wyo. Stat. § 20-5-302: Exclusive, continuing jurisdiction.

(a) Except as provided in W.S. 20-5-304, a court of this state which has made a child custody determination consistent with W.S. 20-5-301 or 20-5-303 has exclusive, continuing jurisdiction over the determination until:

(i) A court of this state determines that the child, the child's parents and any person acting as a parent do not have a significant connection with this state and that substantial evidence is no longer available in this state concerning the child's care, protection, training and personal relationships; or

(ii) A court of this state or a court of another state determines that the child, the child's parents and any person acting as a parent do not presently reside in this state.

(b) A court of this state which has made a child custody determination and does not have exclusive, continuing jurisdiction under this section may modify that determination only if it has jurisdiction to make an initial determination under W.S. 20-5-301.