Senior Airman Joshua Mendoza-Castorillo, 75th Logistics Readiness Squadron, volunteers to sort and bundle holiday cards for distribution throughout Hill Air Force Base, Utah, Dec. 16, 2020. More than 21,000 holiday letters were received from the public through the National Holiday Card Challenge and sent to express support and appreciation for the service of military members and their families. (U.S. Air Force photo by Todd Cromar)