Operation Jefferson Glenn ran from 5 September 1970 to 8 October 1971 and was the last major operation in which U.S. ground forces participated during the Vietnam War and the final major offensive in which the 101st Airborne Division fought. This was a joint military operation combining forces of the 101st Airborne and the Army of the Republic of Vietnam (ARVN) 1st Infantry Division.
Background
The purpose of this operation was to shield critical installations in Huế and Da Nang by patrolling rocket belts along the edge of the mountains. During the 399 days of operations the Allied troops established multiple firebases throughout Thừa Thiên Province and regularly encountered People's Army of Vietnam (PAVN) and Viet Cong (VC) troops.
Operation
1970
On 7 September Troop B, 2nd Squadron, 17th Cavalry Regiment gunships killed 6 PAVN. On 15 September a bomb damage assessment mission by Troop B found 5 PAVN trucks destroyed. On 18 September 1970 Troop A, 2/17th inserted the ARVN 1st Division's Hac Bao Reconnaissance Company resulting in 1 PAVN killed and 1 AK-47 captured and a further 5 PAVN observed killed from previous helicopter attacks. On the same day Troop C gunships destroyed 1 PAVN truck in the A Sầu Valley and follow-up airstrikes destroyed another truck, a .51 calibre machine gun and several bunkers. On 21 September Troop C gunships killed 4 PAVN. From 24–26 September Troop A gunships killed 3 PAVN and US airstrikes killed a further 5. On 28–29 September Troop C gunships killed 2 PAVN.
On 5 October the Troop A, 2/17th aero-rifle platoon was landed to recover two PAVN packs, they engaged and killed 2 PAVN and a mortar position was destroyed by artillery fire killing a further 3 PAVN. On 24 October Troop A, 2/17th found and destroyed 50 boxes of 122mm rocket warheads.
On 11 December the Troop C, 2/17th aero-rifle platoon was inserted at A Lưới Camp to destroy bridges on Route 548. On 16 December a Troop C LOH was shot down by .51 cal fire. On 19 December a Troop C FLIR team killed 10 PAVN.
1971
On 6 January while searching for a downed Troop C AH-1G, Troop B found an AH-1G lost since 1969 near Firebase Veghel and the crew remains were recovered. From 11–25 January Troop A, 2/17th killed 7 PAVN. On 14 January a Troop B LOH was shot down. On 16 January another Troop B LOH was shot down by .51 cal fire. Troop C killed 3 PAVN near Firebase Currahee. On 10 February a Troop B LOH was shot down by 0.51 cal fire in the A Sầu Valley with the 2-man crew missing. On 11–14 February Troop B gunships destroyed 1 truck and a bulldozer in the A Sầu Valley. On 18 February the Troop B aero-rifle platoon was inserted to recover the bodies of US Marine helicopter crewmen. Throughout February and into April 2/17th supported Operation Lam Son 719.
On 1 April Troop B's aero-rifle platoon was inserted to recover a downed AH-1G at Firebase Veghel. On 6 April a Troop B UH-1 on a prisoner capture mission was hit by ground fire resulting in 1 US killed. On 8 April the Troop B aero-rifle platoon was inserted to recover a downed UH-1H. On 10 April the Troop B command and control helicopter was hit by 37mm antiaircraft fire killing the Troop B commander. On 13 April a Troop B LOH was shot down. From 13–15 April Troop A gunships killed 6 PAVN and destroyed a truck in the "Vietnam Salient" south of Route 9 where Vietnam protrudes into Laos. On 15 April Troop D was inserted into the A Sầu Valley for ground reconnaissance. From 19–23 April Troop A supported the ARVN 54th Regiment and 258th Marine Brigade operating near Firebase Holcomb () resulting in 1 PAVN tank and 1 APC destroyed. On 20 April Troop D was again inserted into the A Sầu Valley for ground reconnaissance. On 23 April a Troop B UH-1H flying in support of Vietnamese Rangers was shot down with 1 US killed. On 24 April Troop D was inserted to reinforce a Ranger team in contact, US losses were 5 killed, while PAVN losses were 12 killed. On 26 April while inserting the Hac Bao Company Troop A gunships killed 7 PAVN. From 27–30 April Troop A destroyed numerous PAVN facilities and killed 3 PAVN.