Wyo. Stat. § 41-7-413
The provisions of this article, relative to the levy and collection of payments, charges or assessments in irrigation districts shall not apply to any district which may be organized within a federal reclamation project for the purpose of cooperation between such district and the United States; provided, a different method for the levy and collection of payments, charges or assessments be agreed upon between such district and the United States; and they shall apply only with the modifications hereinafter set forth to an irrigation district which may have been organized within a federal reclamation project when the board of commissioners of such irrigation district by unanimous vote decide to make collection of their taxes or assessments through their own treasurer's office. Whenever the board of commissioners of an irrigation district, organized within a United States reclamation project by unanimous vote of said board decide to make collection of their taxes and assessments through their own office, they shall certify their action to the board of county commissioners of each county in which their district is situated, by a written certificate, which shall be over the signatures of its president and secretary. Such certificate shall be filed in the office of the county clerk of such county not later than July first of the year in which the change of place of payment is desired to be effective and thereafter all taxes or assessments levied or assessed for such district shall be collected by, and payable to the treasurer of the irrigation district, at the office designated by such district at the time and in the manner now fixed by statute. When a certificate is filed as hereinbefore provided, then and thereafter the county commissioners of the county having jurisdiction of such irrigation district shall not be required to certify and deliver said assessment roll to the county assessor of such county or counties as otherwise provided by law, but shall certify and deliver said assessment roll to the treasurer of said district who shall act in lieu of and in place of the county treasurer in sending notices and collecting and receipting for such taxes or assessments. It shall be the duty of the treasurer of any irrigation district, following the method provided herein for collection of taxes or assessments to certify to the county treasurer of the county in which the land is situated the amount of any delinquent taxes or assessments on or before the 25th of May of each and every year and the county treasurer shall enter the same upon his delinquent tax list and make sale thereof as now provided by law. Any district which may or shall choose to make collection of its taxes or assessments as provided herein may revert back to the method of collection through the county treasurer's office by filing with the county clerk of the county or counties within which such district is located, a certificate showing the desire of a majority of its board of commissioners to change. Thereupon beginning with the first of July of the year in which the change is desired to be made, all the requirements of collection through the county treasurer's office shall be complied with.
W.S. 41-7-413