Wyo. Stat. § 18-3-803: Liability for collection of taxes.

Each county treasurer is responsible on his bond for reasonable skill, diligence, good faith and honesty in the performance of his duties. He shall diligently endeavor to collect all taxes due the county and state and is responsible on his bond for willfully, carelessly or negligently allowing taxes to remain unpaid. No county treasurer who has honestly, diligently and in good faith endeavored to collect the taxes shall be held responsible on his bond for any unpaid taxes.