(1) If a rural improvement district includes areas in more than one county, the board of county commissioners of each county in which any portion of the district is situated shall, upon creation of the district and at a joint session, appoint an initial board of three trustees to administer the affairs of the district.
(2) At the end of the term of a trustee, the board of county commissioners of the county represented by the trustee shall appoint a new trustee. In case of a vacancy by death, resignation, removal from the district, or otherwise, a trustee shall be appointed by the board of county commissioners of the county represented by the trustee to fill the vacancy.
(3) At least one trustee shall be appointed from each county within the district.