About 500 U. S. Marines will be deployed to the Yuma border area.

The Marines, from Camp Pendleton, will comprise elements of the 1st Combat Engineer Battalion. The troops will focus on reinforcing border barriers and support security along the U.S. / Mexico border. Federal land along the Arizona border, as well as the Imperial Valley, have been designated as National Defense Areas as part of the crackdown on illegal immigration. Troops will be allowed to detain people suspected of trespassing within the designated areas and turn them over to federal law enforcement. The Marines pointed out that military personnel are not authorized to conduct civilian law enforcement activities  such as search, seizure and arrests.