Wyo. Stat. § 37-2-214
At any time after an order has been made by the commission any person interested therein may apply for a rehearing in respect to any matter determined therein and the commission shall grant and hold a rehearing if in its judgment sufficient reason therefor be made to appear, which rehearing shall be subject to rules as the commission may prescribe. Applications for rehearing shall stay the effect of any order or decision of the commission only as to the portion of the order addressed in the rehearing application until the commission denies the application or enters an order following rehearing, whichever last occurs, provided, however, that upon the request of any party and a showing of good cause therefor, the commission may vacate the stay and allow the order or decision to remain in effect. An order or decision made after the rehearing vacating, amending or modifying the original order or decision shall not, as to the matter considered on rehearing, be open to a further application for rehearing, and shall have the same force and effect as the original order or decision.
W.S. 37-2-214