A Coyote Trainer with Tactical Training Exercise Control Group, Marine Air Ground Task Force Training Command, briefs Marines with Alpha Company, 4th Combat Engineer Battalion, 4th Marine Division, before an obstacle clearing practical application, during Integrated Training Exercise 4-18, aboard MCAGCC Twentynine Palms, California, June 12, 2018. The OCD training was conducted to prepare Marines for the execution of a live-fire combined arms breach in which mechanized units will detonate a 1,000 pound mine clearing charge.