Sioux City Air National Guard Base

Sioux City Air National Guard Base is an Iowa Air National Guard facility located at Sioux Gateway Airport, approximately 7.2 miles south-southeast of Sioux City, Iowa. The airport was named "Colonel Bud Day Field" in 2002. The base is owned by the Department of Defense and operated by the US Air Force, with control by the Iowa Air National Guard. It is currently operational.

The base was established in March 1942 as Sioux City Army Air Base (AAB) and served as a major training center during World War II for B-17 Flying Fortress and B-24 Liberator crews. It closed in December 1945 but reopened in September 1946 under the Air Force Reserve. During the 1950s, it functioned as an Air Defense Command (ADC) fighter-interceptor base. From 1959, it transitioned to an ADC command and control station, hosting the Semi Automatic Ground Environment (SAGE) Data Center (DC-22) for air defense. ADC facilities closed in 1968, and the Iowa Air National Guard became the host unit.

The main unit stationed at the base is the 185th Air Refueling Wing, which provides mid-air refueling and mobility sustainment. The wing also supports the state of Iowa during emergencies. The 174th Fighter Squadron, part of the 185th, has a history of operating various aircraft, including P-51 Mustangs, F-84 Thunderjets, F-80C Shooting Stars, F-84E Thunderstreaks, F-100C Super Sabres, A-7D Corsair IIs, and F-16 Fighting Falcons, before converting to the KC-135 Stratotanker in 2003. The base was also the emergency landing site for United Airlines Flight 232 in 1989, where Air National Guard personnel assisted in the response.