[4][5] It conducted forestry and ancillary operations throughout France, from the Spanish and Swiss borders to the very front lines in Ardennes.

The 20th Engineer Regiment was organized with the mission to provide lumber for combat and support operations for the American Expeditionary Force and its allies, thereby earning the name "Lumberjacks".

[11][12] The 20th Engineer Regiment was reactivated in 1940 at Fort Benning, Georgia, as the United States prepared to enter World War II.

[3] In 1942 the 20th Engineer Regiment sailed to the French protectorate in Morocco where the 2nd Battalion carried out an assault landing on the beaches of Fedala.

[13] The regiment cleared and secured local ports and then fortified the hotel where President Franklin D. Roosevelt and Prime Minister Winston Churchill met for the Casablanca Conference.

[6] The 20th Engineer Regiment marched across North Africa to join the command of General Omar Bradley and the II Corps in the French protectorate of Tunisia.

The regiment conducted a first wave assault landing on the beaches of Sicily and cleared lines of communication to complete the occupation of the island.

[14] The 20th Engineer Battalion was preparing to travel to Asia to carry out an attack on the Japanese home islands when the war finally ended.

During the attack, the 20th Engineers assaulted enemy fortifications, cleared areas of obstacles and unexploded ordnance, and built logistics bases.

[19] In February 1997, Company C along with the divisional cavalry squadron, was deployed to Kuwait on a mission to deter Iraqi aggression.

The 20th Engineers conducted combat patrols, helped re-construct civil infrastructure, and cleared areas of munitions.

Separately numbered, specialized companies and detachments (sapper, route clearance, bridging, mobility augmentation, diving, etc.)

[23] On November 5, 2009, an Arab terrorist shot, wounded, and killed soldiers at Fort Hood as they prepared to deploy to Afghanistan.

[1] The 20th Engineer Battalion was deployed to Afghanistan in 2010 as part of the International Security Assistance Force (ISAF), a component of the North Atlantic Treaty Organization (NATO).

The battalion was responsible for clearing routes and areas of explosive devices, primarily in the provinces of Kandahar, Zabul, and Helmand.

[26] The task force spent a considerable amount of time training engineers of the Afghan National Army.