Wyo. Stat. § 37-13-127
After the expiration of thirty (30) days from the date of the adoption of the resolution levying the assessments, the governing body may issue negotiable interest-bearing bonds in a principal amount not exceeding the unpaid balance of the assessments levied. The bonds shall bear interest payable semiannually or annually and shall mature serially over a period not exceeding twenty (20) years, but in no event shall the bonds extend over a longer period of time than the period of time over which the installments of special assessments are due and payable and ninety (90) days thereafter. The bonds shall be of a form and denomination and shall be payable in principal and interest at times and places and shall be sold, authorized and issued in a manner, as the governing body may determine. The bonds shall be dated no earlier than the date on which the special assessment shall begin to bear interest and shall be secured by and payable from the irrevocable pledge of the funds derived from the levy and collection of the special assessments in anticipation of the collection of which they are issued. Any premium received on the sale of the bonds shall be placed in the fund for the payment of principal and interest on the bonds. The bonds shall be callable for redemption from the proceeds of the sale of property sold for the nonpayment of special assessments but not otherwise unless the bonds on the face thereof provide for redemption prior to maturity. The governing body may provide that the bonds shall be redeemable on interest payment date or dates prior to maturity pursuant to notice and at premiums as it deems advisable. The bonds shall be signed by a member of the governing body designated by the governing body and shall be countersigned by the city recorder or the clerk of the board of the town trustees or the clerk of the board of the county commissioners, whichever is applicable, and one (1) of the signatures may be a facsimile signature. Interest may be evidenced by interest coupons attached to the bonds and signed by a facsimile signature of one (1) of the individuals who signed the bond.
W.S. 37-13-127