On 1 April 1959, ADC's 30th Air Division, operating the Semi Automatic Ground Environment (SAGE) system, replaced the 37th AD.

The 20th AD was responsible for air defense of parts of Wisconsin, Minnesota, Iowa, Missouri, Arkansas, Tennessee, Kentucky, Indiana, and all of Illinois.

It also supervised Air National Guard units that flew interception sorties using, among others, the F-101 Voodoo and F-106 Delta Dart aircraft, while at the same time controlling numerous ground-based USAF radar squadrons.

On 31 December 1967, the 20th AD was reassigned to Fort Lee AFS, Virginia and Truax AFB was deactivated as an active Aerospace Defense Command base in early 1968.

The 115 FW maintains mobilization readiness as part of the Air Reserve Component (ARC) and conducts training as directed by ACC.

The State mission under Title 32 USC is to provide trained and equipped units to protect life and property and to preserve peace, order, and public safety as directed by the Governor of Wisconsin.

In April 2020, the Air Force announced that the F-35A Lightning II would be based at Truax Field, with the 115th Fighter Wing receiving its first aircraft in 2023.