U.S. Marines with several units within the I Marine Expeditionary Force observed a display of how to load and stack a shipping container during Pacific Horizon on Camp Pendleton, Calif., July 12, 2017. Pacific Horizon 2017 is a Maritime Prepositioning Force (MPF) exercise designed to train I Marine Expeditionary Force (I MEF) and components of Naval Beach Group 1 (NBG-1) Marines and Sailors on arrival and assembly operations as well as follow-on Marine Air Ground Task Force actions to ensure that the right equipment, supplies and tools get to the right people to be employed in a crisis response, humanitarian assistance and amassing combat power ashore from sea. (U.S. Marine Corps photo by Lance Cpl. Roxanna Gonzalez) - U.S. Marines with several units within the I Marine Expeditionary Force observed a display of how to load and stack a shipping container during Pacific Horizon on Camp Pendleton, Calif., July 12, 2017. Pacific Horizon 2017 is a Maritime Prepositioning Force (MPF) exercise designed to train I Marine Expeditionary Force (I MEF) and components of Naval Beach Group 1 (NBG-1) Marines and Sailors on arrival and assembly operations as well as follow-on Marine Air Ground Task Force actions to ensure that the right equipment, supplies and tools get to the right people to be employed in a crisis response, humanitarian assistance and amassing combat power ashore from sea. (U.S. Marine Corps photo by Lance Cpl. Roxanna Gonzalez)