31st Engineer Battalion The 31st Engineer Battalion is a combat Engineer Battalion in the U . S . Army History . The 31st Engineer Battalion of the United States Army was originally constituted as the 31st Engineer Company on 1 July 1940 and activated at Fort Belvoir , Virginia . The unit was reorganized , expanded and redesignated on 15 December 1941 as the 31st Engineer Combat Battalion . On 29 April 1942 the unit was reorganized and redesignated as the 1st Battalion , 31st Engineers ( Combat ) , and then again on 1 August 1942 as the 31st Engineer Combat Regiment . After being re - designated as the 31st Engineer Combat Regiment , the regiment was broken up on 22 March 1943 and its elements were then reorganized and redesignated as follows : 1st Battalion as the 31st Engineer Combat Battalion , Headquarters and Headquarters and Service Company as Headquarters and Headquarters Company , 1114th Engineer Combat Group , 2nd Battalion as the 241st Engineer Combat Battalion . The 31st Engineer Combat Battalion remained at Fort Belvoir until 10 June 1944 and then served for four months at Camp Butner , North Carolina . The 31st Engineer Combat Battalion departed New York Port of Embarkation on 22 October 1944 aboard the General William Black for overseas service . They arrived in England on 2 November 1944 and landed in France on 31 December 1944 and were assigned to Seventh Army . It then moved to Bouxwiller in the French Alsace and installed defense against a possible renewed German attack in the region . The battalion entered Germany in late March 1945 and crossed the Rhine near Mannheim on the last day of that month . It encountered its toughest fighting of the war on 4 – 8 April as it sought to bridge the Neckar River near Heilbronn . The battalion then swung south , crossing the Danube at Ulm and entering Austria on 9 May . After serving for a time on occupation duty in Vienna , the 31st Sailed back from Le Havre , France , on 26 February 1946 and arrived in New York Port of Embarkation on 7 March 1946 . Two days later , the 31st Engineer Combat Battalion inactivated at Camp Kilmer , New Jersey . On 10 March 1951 , the battalion activated at Camp McCoy , Wisconsin , during the Korean War . It served there for two years before it was redesignated on 8 June 1953 as the 31st Engineer Battalion ( Combat ) and moved to Fort Carson , Colorado . On 15 December 1956 , the battalion inactivated . The unit was again activated on 17 June 1963 at Fort Chaffee , Arkansas . The battalion departed Fort Bliss , Texas for overseas service and arrived at Vung Tau , Vietnam on 24 March 1968 . The battalion was responsible for III CTZ airmobile equipment support and construction support under the 159th and 79th Engineer Groups just north of Saigon . The unit moved to Phuoc Vinh on 1 July 1968 and to Long Binh in mid - 1971 where it remained until it departed Vietnam for return to the United States . After nearly four years of service in Vietnam , the battalion returned to Fort Lewis , Washington , and was inactivated there on 12 March 1972 . On 30 September 1986 , the “ Second to None ” 31st Engineer Battalion transferred to the United States Army and Doctrine Command ; concurrently , Headquarters organized at Fort Leonard Wood , Missouri and redesignated the “ We Demonstrate ” 31st Engineer Battalion . On 20 August 1990 , the 132nd Engineer Brigade inactivated . The 31st Engineer Battalion then became part of the 1st Engineer Brigade . From January to March 1991 , the battalion began preparing Soldiers for Operation Desert Storm , and supported the mobilization of the 1st Battalion , 392nd Regiment , 98th Division ( Training ) based in New York State . The battalion was reassigned from the 1st Engineer Brigade to the 3rd Training Brigade on 6 May 1991 . Along with the 35th and 589th Engineer Battalion , the 31st joined the five battalions of the 10th Infantry Regiment . In January 1992 , Delta Company was inactivated , and Echo Company was redesignated as Delta Company . In June 1993 , Alpha Company was redesignated E / 35th ; Bravo and Charlie Companies turned provisional and fell under the control of the 35th Engineer Battalion on 1 October 1993 . Delta Company inactivated with the battalion on 15 October 1993 . Today the 31st Engineer Battalion once again is based at Fort Leonard Wood , Missouri under the 1st Engineer Brigade . Lineage . Constituted 1 July 1940 in the Regular Army as the 31st Engineer Company and activated at Fort Belvoir , Virginia Regiment broken up 22 March 1943 and its elements reorganized and redesignated as follows - 31st Engineer Combat Battalion inactivated 9 March 1946 at Camp Kilmer , New Jersey Headquarters transferred 30 September 1986 to the United States Army Training and Doctrine Command and activated at Fort Leonard Wood , Missouri Campaign participation credit . World War II : Rhineland ; Ardennes - Alsace ; Central Europe Vietnam : Tet Counteroffensive ; Counteroffensive , Phase IV ; Counteroffensive , Phase V ; Counteroffensive , Phase VI ; Tet 69 / Counteroffensive ; Summer - Fall 1969 ; Winter - Spring 1970 ; Sanctuary Counteroffensive ; Counteroffensive , Phase VII ; Consolidation I ; Consolidation II