The 340th Engineers was a new regiment activated at Vancouver Barracks, Washington on 5 March 1942. The nucleus of this unit was a cadre of seven officers and 72 enlisted men from the 18th Combat Engineers who arrived on 9 March 1942. Another cadre of 62 enlisted men from Ft. Francis E. Warren also arrived on 9 March of 42. The Remainder of officers and men arrived from Ft. Leonard Wood, Missouri during the later part of March. Colonel F. Russel Lyons,age 52 and a civil engineer graduate of Rensselaer Polytechnic Institute in Troy, N.Y, arrived March 27, 1942 as their Commanding Officer.
