Yaak Air Force Station

Yaak Air Force Station (ADC ID: P-11) is a closed United States Air Force General Surveillance Radar station. It is located 25.1 mi west of Rexford, Montana. It was closed in 1960.

History
Yaak Air Force Station was one of twenty-eight stations built as part of the second segment of the Air Defense Command permanent radar network. Prompted by the start of the Korean War, on July 11, 1950, the Secretary of the Air Force asked the Secretary of Defense for approval to expedite construction of the permanent network. Receiving the Defense Secretary’s approval on July 21, the Air Force directed the Corps of Engineers to proceed with construction.

The 680th Aircraft Control and Warning Squadron was activated at Yaak AFS on 1 March 1951, and initially the station functioned as a Ground-Control Intercept (GCI) and warning station. As a GCI station, the squadron's role was to guide interceptor aircraft toward unidentified intruders picked up on the unit's radar scopes. The squadron began operating AN/FPS-3 and AN/FPS-4 radars at this northern-tier site in April 1952. An AN/FPS-6 was added in 1956, and the AN/FPS-4 was replaced by an AN/GPS-3 in 1957.

In addition to the main facility, Yaak operated several AN/FPS-14 Gap Filler sites:
 * Porthill, ID        (P-11A) 48.99333°N, -116.48083°W
 * Eureka, MT          (P-11B) 48.86472°N, -115.12556°W
 * Moyie Springs, ID   (P-11C) 48.76333°N, -116.20944°W

The 680th AC&W Squadron was inactivated on 1 July 1960, but would be reborn the following year as the 680th Radar Squadron (SAGE) at Palermo AFS, New Jersey (site Z-54).

This station at Yaak was converted into an unmanned gap-filler radar site in 1960, and redesignated SM-151E, supporting the 823d AC&W Squadron at Mica Peak AFS, Washington and later the 716th AC&W Squadron at Kalispell AFS, Montana as TM-179B. It was closed in the 1960s.

The main station was declared excess by the Air Force to GSA in 1960 and 1961, and transferred by the Corps of Engineers to the Forest Service in 1965, but the 90.0 acre portion obtained by special use permit was transferred to the Forest service earlier in 1962. The Forest Service used only the access road since the property was transferred to them in 1965 and 1967, for the purpose of ingress and egress to a fire lookout point not located within the bounds of the former facility.

Nothing currently remains of the former Air Force Station/Gap Filler Annex. Concrete and metal rubble resulting in building demolition was located throughout the area.