It is a United States Army Reserve formation and is subordinate to the 416th Theater Engineer Command.

The Commander, 420th Engineer Brigade commands and controls all Army Reserve engineer units in the states of Texas, Arkansas, Louisiana, Oklahoma, Missouri, Colorado, and New Mexico consisting of approximately 4,500 reserve soldiers.

They have also participated in Exercises Bright Star in Egypt, Fuerte Caminos in Honduras and Belize, and Nuevas Horizontes in El Salvador, Panama, and Guatemala.

The brigade is a subordinate unit of the 416th Theater Engineer Command (Darien, Illinois).

The brigade contains three subordinate battalions:[1] Constituted 13 February 1951 in the Organized Reserve Corps as Headquarters and Headquarters Company, 420th Engineer Aviation Brigade Activated 15 February 1951 at College Station, Texas (Organized Reserve Corps redesignated 9 July 1952 as the U.S Army Reserve) Reorganized and redesignated 30 April 1953 as Headquarters and Headquarters Company, 420th Engineer Brigade Redesignated 8 November 1955 as Headquarters and Headquarters Company, 420th Engineer Aviation Brigade Redesignated 15 January 1957 as Headquarters and Headquarters Company, 420th Engineer Brigade Location changed 3 November 1958 to Bryan, Texas Ordered into active military service 7 December 2003 at Bryan, Texas; released from active military service 3 June 2005 and reverted to reserve status Ordered into active military service 15 March 2008 at Bryan, Texas This article incorporates public domain material from Lineage and Honors 420th Engineer Brigade.