Wyo. Stat. § 9-1-801: Office created; mandatory and permissive establishment.

There shall be in each judicial district in which any one (1) county has reached a population of sixty thousand (60,000) or more the office of district attorney. In each of the remaining judicial districts there shall be the office of district attorney whenever a majority of the county commissioners in each county within the judicial district shall resolve that such an office of district attorney should be created in that judicial district.