Wyo. Stat. § 41-3-322
The owner of each reservoir shall annually, in writing, before or during the irrigating season and before the releasing of the water from the reservoir, deliver to the water commissioner having jurisdiction over such reservoir a list or lists of parties entitled to use water from such reservoir during the irrigating season of such year, and also a list as near as may be of the lands proposed to be irrigated, and shall immediately notify such water commissioner of any changes in such list or lists. The superintendent of the water division in which such reservoir is situated shall annually on or before the first day of December in each year make a written report to the state engineer of the state, enumerating in detail the person or persons who during the irrigating season immediately preceding use any part of such reservoir water, and shall also enumerate therein the lands upon or uses for which said water was applied during such irrigating season so that the state engineer may be kept at all times advised as to whether or not such water has been applied to beneficial uses.
W.S. 41-3-322