The Phoenix Airgun Bench Rest and Silhouette club hosts a formal competition the first Saturday of each month at the Rio Salado Sportsman's Club.
Located just east of Mesa, Arizona you'll find airgun friendly features such as forty benches under covered shooting positions as well as electronic scoring. Better yet, the cold water is free.
Spring gunners are especially welcome as there is a separate spring piston rifle class
Go to the Rio Salado Sportsman's Club website and click the "Airgun/Benchrest" link under the "Divisions" icon for additional information