Prior to the invasion of the Republic of Korea by the North Korean communists in 1950, the area now designated Osan Air Base consisted of four villages near the hillsides and a larger number of rice paddies where the runway now lies. Originally designated K-55, the base was redesignated as Osan Air Base in late 1956.
The base was not named for any of the villages on the site, but for the small town of Osan-up, about six miles to the north on the main supply route leading to Seoul. The Korean word "O-san" means Crow Hill. Koreans who were employed at the base at the time believed that the name of Osan was chosen by the Americans because it was much easier to pronounce and spell than the other villages' names. Osan was also the closest village to be found on military maps of the area at that time.
The four villages which were moved to make room for the base were Jeuk-Bong-Ri, Chang-Deung-Ri, Shin-Ya-Ri and Ya-Ri. A large ginkgo tree that was in the village square of one of these villages still stands on the present golf course site. The newest dining facility near this location is the Ginko Tree Dining Facility. Osan is on and near the site of two significant events which occurred early in the Korean War. The first Korean War battle between North Korean and U.S. forces was fought just a few miles north of present day Osan Air Base. Following the orders of Maj. Gen. William F. Dean, commander of the 24th Infantry Division, a task force of two infantry companies and an artillery battalion was sent to Korea July 1, 1950.Under the command of Lt. Col. Charles B. Smith, this group, called "Task Force Smith," was tasked to meet the oncoming North Koreans to bolster the faltering Korean army and provide a delaying action until the rest of the division could be transported to the peninsula. On July 5, 1950, "Task Force Smith" was hit by enemy fire between the towns of Osan and Suwon. The task force held against an entire communist division for 7 hours. With ammunition depleted, the survivors managed to fight their way clear and reach Pyongtaek. There, joining an element of the 34th Infantry Regiment, they soon had to give up this position, almost without a fight.Task Force Smith MemorialJust north of Cheonan, the task force fought another delaying action, but soon was pulled back to Taejon where General Dean had established his headquarters. "Task Force Smith" fought for 16 days, culminating its delaying action by holding the North Korean army outside of Taejon. That enabled the 24th Infantry Division to land at Pusan and hold the Pusan perimeter until the famous Inchon landing September 15, 1950.Topping a hill a few miles north of Osan on the road to Suwon a monument was constructed by Companies B and C of the 3rd Engineering Battalion, 24th Infantry Division, in honor of the men who gave their lives in the valley. The inscription on the plaque reads: "In commemoration of this site, 5 July 1950, 406 men of Task Force Smith, 21st Infantry Regiment and Battery, 57th Field Artillery Battalion, 24th Infantry Division, fought the initial action between United States and Communist Troops." Osan also is remembered as the location for the first U.S. Army company-strength bayonet charge since World War I, which occurred on February 7, 1951. That charge was part of a larger plan to clear the Republic of Korea of all communist troops south of Seoul. Army Captain Lewis L. Millet led his soldiers against communist Chinese forces on Hill 180, which dominates present day Osan Air Base.For his heroic actions, Captain Millet received the Medal of Honor. A plaque on Hill 180 commemorates this event, and one of the roads leading up the hill is named for Captain Millett.
Prior to its use as an air base, Osan's site housed an army regiment. In addition, Osan Air Base is the only American base in Korea built completely "from scratch" since there had never been a Japanese, Korean or American air strip on the location. The site was chosen as the locale for a two-wing base and 5th Air Force Advanced headquarters. Fifth Air Force at that time was headquartered in its forward location in Seoul and its rear location at Taegu.
In November 1951, work began on building two roads, one for hauling bombs and the other to service the administrative area. The 839th Engineer Aviation Battalion began runway construction July 9, 1952. (A pictorial record of the construction is available in a slide show.) The rolling hills were transformed into a base of operation and the runway was completed in less than 6 months.
The runway opened in December 1952, with the advance elements of the 18th Fighter Bomber Wing arriving for duty late in the month. The 18th Fighter Bomber Wing provided air operations in support of United Nations ground forces during the conflict. After the conflict, the unit was transferred back to Kadena Air Base, Japan, and was replaced by the 58th Fighter Bomber Wing.
Fifth Air Force advanced headquarters moved to Osan in February 1954 and remained until the following September. During 1954 and 1955, the 58th Fighter Bomber Wing moved to Osan from Taegu. The 58th Air Base Group became independent of the wing in March 1957 and assumed host unit responsibilities.
The 51st Air Base wing was relocated from Naha Air Base, Okinawa, to Osan November 1, 1971, and took over support responsibilities. It was redesignated the 51st Composite Wing (Tactical) on September 30, 1974. On July 1, 1982, the 51st Composite Wing was redesignated the 51st Tactical Fighter Wing. Ten years later, in February 1992, the wing was redesignated the 51st Wing and on October 1, 1993 it was redesignated the 51st Fighter Wing, its current designation.
The 51st Fighter Wing Headquarters building is located on the now famous Hill 180. Today, Osan Air Base covers 1,661 acres for exclusive USAF use, and is acquiring an additional 425 acres under the Land Purchase Plan (LPP) as part of the consolidation of USFK facilities in Korea. One of Osan's most prominent features is it's 9,000-foot runway.
Osan Air Base is also home to the Republic of Korea Air Force (ROKAF) Operations Command (AFOC). The ROKAF occupies an additional significant area within Osan AB, and recently expanded into land that had originally been purchased to accommodate the relocation of forces from Yongsan Army Garrison. When that move was cancelled, the ROKAF acquired the land. The new AFOC headquarters is located in the expansion area.
Osan AB is located approximately 34 miles south of Seoul. South Korea is slightly larger than the state of Indiana. It is bordered by North Korea on the north and is only 123 miles from Japan to the east.