Wyo. Stat. § 41-3-320
Except as otherwise provided by deed or other written instruments of the owner or owners of the right to impound water in any reservoir, such reservoir owner or owners shall, after the completion of the works in connection with such reservoir, be held to be the owner of the right to impound the water, and the right to sell or lease a portion or all his right to the impounded waters; provided, that the sale of any portion of the capacity of any reservoir shall carry with it an interest in the reservoir and works appurtenant thereto of such proportion as the portion sold bears to the total capacity of the reservoir; and provided, further, that the water stored in any reservoir cannot be used outside the boundaries of the state of Wyoming without special permit from the state engineer; and provided, further, that the state engineer may deny any use of water from any reservoir that would be detrimental to the public interest.
W.S. 41-3-320