Oklahoma Army National Guard members of 1st Squadron, 180th Cavalry Regiment, 45th Infantry Brigade Combat Team, held a transfer of authority ceremony in Kabul, Afghanistan, Dec. 31, 2017, alongside members of 3rd Squadron, 73rd Cavalry Regiment, 1st Brigade Combat Team, 82nd Airborne Division, representing the transfer of mission from one organization to another. (U.S. Army photo/Lina Castillo)