Wyo. Stat. § 37-2-123: Order apportioning expenses between joint public utilities.

Whenever any order of the commission involves expenditures of any sum or sums by public utilities rendering any joint service or services, and the public utilities affected thereby shall fail to agree upon the division or apportionment thereof within a reasonable time after the service of such order, the commission may issue a supplemental order declaring the apportionment or division of such expense.