Territory Overview:
The Marine Corps West Field Office has a vast area of responsibility, including northern San Diego County, southern Orange County, Riverside, and San Bernardino County.  The Marine Corps West Field Office is also responsible for NCIS support to all of Arizona, Colorado, Nevada, Utah, New Mexico; and the Texas counties of El Paso, Hudspeth, Reeves, and Culbertson.

The Field Office includes NCIS Resident Agency (NCISRA) Camp Pendleton; NCISRA Miramar; NCISRA Twenty-Nine Palms, NCISRA Yuma, and NCIS Resident Unit (NCISRU) Fallon.

Investigative Units:
The Marine Corps West Field Office is comprised of four squads: General Crimes, Family and Sexual Violence, Special Operations, and Counterintelligence/Counter Terrorism. 

The General Crimes squad focuses on providing a timely, efficient, and comprehensive response to criminal activity.  With the support of a skilled Major Case Response Team, the squad works more death investigations than any other NCIS office.  The majority of investigations initiated by the Family and Sexual Violence squad involve adult sexual assaults, child pornography, and child sex abuse complaints.  The team maintains an aggressive crime prevention briefing program with an end goal of reducing crime within the United States Marine Corps.  The Special Operations squad targets criminal threats by exploiting available criminal intelligence and initiating high impact operations. The Counterintelligence and Counter Terrorism squad focuses on identifying and neutralizing terrorists and intelligence threats in the Marine Corps West Field Office area of responsibility through the deployment of numerous investigative capabilities.