Master Chief Petty Officer Christopher D. Kotz, command master chief of Marine Forces Reserve and Marine Forces North, answers questions from Marines and Sailors with Combat Logistics Battalion 453 in Aurora, Colo., Jan. 17, 2017. The visit was part of the commemoration of the Marine Corps Reserve Centennial. From World War I through the wars in Iraq and Afghanistan, the Marine Corps Reserve has played an essential role in the Marine Corps Total Force by augmenting and reinforcing the active component across the full range of military operations. (U.S. Marine Corps photo by Lance Cpl. Dallas Johnson/Released)