Hill Air Force Base is a major U.S. Air Force (USAF) base located in Davis County, Utah, just south of the city of Ogden, and bordering the Cities of Layton, Clearfield, Riverdale, Roy, and Sunset with its largest border immediately adjacent to Clearfield and Layton. It is about 30 miles (48 km) north of Salt Lake City. The base was named in honor of Major Ployer Peter Hill of the U.S. Army Air Corps, who died test-flying NX13372, the original Model 299 prototype of the B-17 Flying Fortress bomber. As of 2018, Hill AFB is the sixth-largest employer in the state of Utah. Hill AFB is the home of the Air Force Materiel Command's (AFMC) Ogden Air Logistics Complex (OO-ALC) which is the worldwide manager for a wide range of aircraft, engines, missiles, software, avionics, and accessories components. The OO-ALC is part of the Air Force Sustainment Center.