Hill Air Force Base is a major U.S. Air Force base located in northern Utah, just south of the city of Ogden, and near the towns of Layton, Clearfield, Riverdale, Roy, and Sunset. It is about 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.