Cav cannoneers move to clear the area as a CH47 Chinook brings in a 105mm howitzer and a load of ammo for a new 1st Battalion, 21st Artillery, gun emplacement and landing zone. Source: The First Air Cavalry Division, Vietnam, Volume 1, 1965-1969. Note: This is an undated photo but the tour book covers the period from 1965 to 1969.