Wyo. Stat. § 40-14-337: Notice of assignment.

The debtor is authorized to pay the original lender until he receives notification of assignment of rights to payment pursuant to a consumer loan and that payment is to be made to the assignee. A notification which does not reasonably identify the rights assigned is ineffective. If requested by the debtor, the assignee must seasonably furnish reasonable proof that the assignment has been made and unless he does so the debtor may pay the original lender.