Wyo. Stat. § 15-6-409
The city or town, in the ordinance confirming the assessment roll, shall prescribe the time within which the assessment or installments thereof shall be paid and shall provide for the payment and collection of interest thereon at a rate established by ordinance. Assessments or installments thereof, when delinquent, in addition to interest, shall bear a penalty of not more than five percent (5%) as prescribed by general ordinance. Interest and penalty shall be included in and made a part of the assessment lien. All local assessments becoming a lien upon any property in any city or town shall be collected by the treasurer, and all liens shall be enforced in the manner provided. In cities and towns other than cities of the first class, delinquent assessments or delinquent installments thereof shall be certified to the treasurer of the county in which the city or town is located, and he shall enter them upon the general tax rolls and collect them as other general taxes are collected. The county treasurer shall remit to the city treasurer on the tenth of each month all sums so collected.
W.S. 15-6-409