The Marines on the Combat Center in Twentynine Palms will hold a non-combatant evacuation operation exercise today (Friday April 16). The exercise will be held at the Lance Corporal Torrey Gray Field on the base from 1 to 10 p.m. Roads around the field will also be closed during that time: Sturgis Road, Fifth and Sixth Streets, and the Del Valle track and field. Areas closed from 4 to 10 p.m. are Third Street between Bourke and Del Valle, and Del Valle Road from First to Fourth Streets.