Wyo. Stat. § 3-3-703

(a) When a claim is filed with the clerk it shall be supported by satisfactory vouchers or other evidence supporting the claim, and by the affidavit of the claimant or someone in his behalf that the account is justly due, or if it is not due, when it will or may become due, that no payments have been made thereon which are not credited, and that there are no offsets to the claim to the knowledge of the affiant. If the claim is not due when filed or is contingent, an explanation of the claim shall be stated.

(b) If the claim is founded on a bond, bill, note or other instrument, a copy of the instrument shall accompany the claim. The original instrument shall be exhibited to the conservator if demanded, unless it is lost or destroyed, in which case the claimant shall accompany his claim by his affidavit containing a copy or particular description of the instrument and stating its loss or destruction. If the claim, or any part thereof, is secured by a mortgage or other lien which has been recorded or filed in the office of the county clerk in the county in which the land or property affected by it is situate, it is sufficient to describe the mortgage or lien and refer to the date, filing number and volume and page of its record.