315th Engineer Battalion
The 315th Engineer Battalion is a multi-role engineer battalion of the United States Army based in Camp Pendleton, California. Activated 16 October 2009 at Camp Pendleton, the battalion traces its lineage back to World War I. It is a United States Army Reserve formation and is subordinate to the 301st [Maneuver Enhancement Brigade] out of Fort Lewis, WA.
Organization
The battalion is a subordinate unit of the 301st Maneuver Enhancement Brigade. As of January 2026 the battalion consists of the following units:- 315th Engineer Battalion, at Camp Pendleton
- * Headquarters and Headquarters Company, 315th Engineer Battalion, at Camp Pendleton
- * Forward Support Company, 315th Engineer Battalion, at Camp Pendleton
- * 305th Engineer Company, in San Diego
- * 350th Engineer Company, in Bell
- * 387th Engineer Company, in Scottsdale
- * 394th Engineer Company, in Bell
- * 450th Engineer Platoon, at Camp Pendleton
Lineage
Organized in August 1917 at Camp Travis, Texas
Demobilized 26 June 1919 at Camp Dodge, Iowa
Reconstituted 24 June 1921 in the Organized Reserves as the 315th Engineers, an element of the 90th Division
Organized in November 1921 at San Antonio, Texas
Regiment reorganized and redesignated 30 January 1942 as the 315th Engineer Battalion, an element of the 90th Division
Ordered into active military service 25 March 1942 at Camp Barkeley, Texas
Reorganized and Redesignated 15 September 1942 as the 315th Engineer Motorized Battalion
Reorganized and redesignated 19 May 1943 as the 315th Engineer Combat Battalion
Inactivated 22 December 1945 at Camp Patrick Henry, Virginia
Activated 28 April 1947 at San Antonio, Texas
Reorganized and redesignated 6 April 1953 as the 315th Engineer Battalion
Inactivated 31 December 1965 at Houston, Texas, and relieved from assignment from the 90th Infantry Division
Headquarters activated 16 October 2009 at Camp Pendleton, California.
315th Engineer Battalion deployed in 2014 ISO OEF - Afghanistan.
As of June 2021, Battalion is pending relocation to Miramar MCAS - East.