Neb. Rev. Stat. § 39-873: Neb. Rev. Stat. § 39-873

Any power granted to a county in Nebraska by sections 39-855 to 39-876 may be exercised by the county independently or in cooperation with or in aid of similar action by any other county or city in Nebraska, or any county or city in an adjoining state, or in cooperation with the State of Nebraska or any adjoining state or states, or the government of the United States.