Wyo. Stat. § 37-2-119
In conducting any investigation pursuant to the provisions of this act the commission may investigate, consider and determine such matters as the cost or value, or both, of the property and business of any public utility, used and useful for the convenience of the public, and all matters affecting or influencing such cost or value, the operating statistics for any public utility both as to revenues and expenses and as to the physical features of operation in such detail as the commission may deem advisable; the earnings, investment and expenditures of any such corporation as a whole within this state, and as to rates in plants of any water, electrical or gas corporations, the geographical location thereof shall be considered as well as the population of the municipality in which such plant is located.
W.S. 37-2-119