Wyo. Stat. § 41-7-406
Omission to assess benefits, or to assess for construction, or to make additional assessment, or to make assessment for operation, maintenance or repairs against any land or person which should have been assessed, or to award damages to any one (1) or more tracts of lands or easements in an irrigation district shall neither affect the jurisdiction of the court to confirm the report nor to render the benefits assessed, or the assessments for construction, or additional assessments, or assessments for operation, maintenance, or repairs against other lands, or assessments against any person voidable, but the commissioners of said irrigation district shall thereafter, as soon as they discover the omission, or receive notice thereof, either agree with the omitted parties upon the proper award or assessments and award the damages or make such assessment of benefits or assessments for construction, operation, maintenance or repair, and make such additional assessments against the omitted lands and corporations, and award such damages as shall be just, and report the facts, together with such assessments and awards, to the court.
W.S. 41-7-406