Wyo. Stat. § 16-1-101
In exercising, performing or carrying out any power, privilege, authority, duty or function legally vested in any one (1) or more of them by Wyoming law, the state of Wyoming, and any one (1) or more of its counties, municipal corporations, school districts, special districts, public institutions, agencies, boards, commissions and political subdivisions, and any officer or legal representative of any one (1) or more of them, may cooperate with and assist each other, and like entities or authorities of other states, the United States and the Eastern Shoshone and Northern Arapaho tribes of the Wind River Indian Reservation. Cooperation may be informal or subject to resolution, ordinance or other appropriate action, and may be embodied in a written agreement specifying purposes, duration, means of financing, methods of operations, termination, acquisition and disposition of property, employment of executive and subordinate agents, reciprocation of governmental immunity protections or other limitations of liability pursuant to W.S. 16-1-104(f) and other appropriate provisions.
W.S. 16-1-101