Wyo. Stat. § 41-4-316
It shall be the duty of the state engineer or some qualified assistant, to proceed at the time specified in the notice to the parties on said stream, to be adjudicated, to make an examination of said stream, and the works diverting water therefrom, said examination to include the measurement of the discharge of said stream, and of the carrying capacity of the various ditches and canals diverting water therefrom; an examination of the irrigated lands and an approximate measurement of the lands irrigated, or susceptible of irrigation from the various ditches and canals, which said observation and measurements shall be reduced to writing, and made a matter of record in his office; and it shall be the duty of the state engineer to make, or cause to be made, a map or plat on a scale of not less than one (1) inch to the mile, showing, with substantial accuracy, the course of said stream, the location of each ditch or canal diverting water therefrom, and the legal subdivisions of lands which have been irrigated, or which are susceptible of irrigation from the ditches and canals already constructed.
W.S. 41-4-316