Wyo. Stat. § 41-4-303: Notice; by mail to claimants.

It shall also be the duty of said division superintendent to mail to each party having a recorded claim to waters of said stream, by registered mail, a similar notice setting forth the date when the state engineer, or his assistant, will begin the examination of the stream and ditches diverting water therefrom, and also the date when the superintendent will begin the taking of testimony, and the date when the taking of such testimony by said division superintendent shall close.