Redesignated 19 March 1959 as Headquarters and Headquarters Battery, 4th Howitzer Battalion, 77th Artillery; concurrently, withdrawn from the Regular Army, allotted to the Army Reserve, and assigned to the 90th Infantry Division (organic elements concurrently constituted). Battalion activated 1 April 1959 with Headquarters at Austin, Texas. Inactivated 15 March 1963 at Austin, Texas, and relieved from assignment to the 90th Infantry Division.

Redesignated 1 September 1968 as the 4th Battalion, 77th Artillery; concurrently, withdrawn from the Army Reserve, allotted to the Regular Army, assigned to the 101st Airborne Division, and activated at Fort Sill, Oklahoma.

The Battalion arrived in Vietnam on 17 October 1968 under the command of LTC Roger Bartholomew. This Battalion had some pilots from the original 2nd Battalion (ARA), 20th Artillery but also had many who had never seen combat. When the unit arrived in country, a few more pilots were transferred from the prototype 2/20th ARA.

Most notable of the 101st Airborne Division's combat actions were Hamburger Hill in 1969 and Firebase Ripcord in 1970. The Division served in the northern I Corps area of operations against the NVA infiltration routes through Laos and the A Shau Valley. The Division supported the ARVN Operation Lam Son 719 which involved invading southern Laos in 1971, but only aviation units actually entered Laos.

The battalion was redesignated 1 September 1971 as the 4th Battalion, 77th Field Artillery. The Battalion departed Vietnam 4 January 1972 when it returned to Fort Campbell, Kentucky.