Wyo. Stat. § 35-2-437
When the assessed valuation of the property within a hospital district exceeds three million dollars ($3,000,000.00), the board of trustees for that hospital district may divide the district into no more than three (3) trustee districts and provide for the election of at least one (1) trustee from each trustee district. To become effective, the rule creating trustee districts shall be approved by order of the board of county commissioners of the county in which the greater area of property within the district is located. All trustees shall be residents or property owners of the trustee district from which elected. The board of trustees may provide for the trustees to be elected at-large if these trustees are residents of the hospital district.
W.S. 35-2-437