Wyo. Stat. § 1-12-105: Right of witness to demand fees; failure to pay; payments noted.

After the case is called for trial and before a witness is sworn, he may demand his traveling fees and fees for one (1) day's attendance. If the fees are not paid he is not obliged to testify. At the commencement of the trial each day after the first day he may demand his fees for that day's attendance and if the fees are not paid he shall not be compelled to remain. The clerk shall note the payment of fees in the witness book.