Klamath Air Force Station Klamath Air Force Station ( ADC ID : P - 33 , NORAD ID : Z - 33 ) is a closed United States Air Force General Surveillance Radar station . It is located northwest of Klamath , California . It was closed in 1981 . History . Klamath 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 adjacent to the town of Requa , California , about 3 miles northwest of the town of Klamath and within sight of the mouth of the Klamath River . The 777th Aircraft Control and Warning Squadron ( AC & W Sq ) was activated at the new station on 18 December 1950 as a " Lashup - Permanent " site ( LP - 33 ) , operating an AN / TPS - 1 B radar . The site then became a part of the Permanent radar network , 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 . Beginning in April 1952 , the 777th AC & W Sq began operating AN / FPS - 3 and AN / FPS - 4 radars at this northern California coastal site . In 1956 the Air Force added an AN / GPS - 3 radar to the facility . By 1958 an AN / FPS - 20 and AN / FPS - 6 radar had replaced the initial pair of radars . During the following year , an AN / FPS - 6A height - finder radar was added , later modified to an AN / FPS - 90 . The AN / GPS - 3 was removed . During 1960 Klamath AFS joined the Semi Automatic Ground Environment ( SAGE ) system , feeding data to DC - 13 at Adair AFS , Oregon . After joining , the squadron was re - designated as the 777th Radar Squadron ( SAGE ) on 15 July 1960 . The radar squadron provided information 24 / 7 the SAGE Direction Center where it was analyzed to determine range , direction altitude speed and whether or not aircraft were friendly or hostile . By the end of 1961 , the AN / FPS - 20A long - range search radar had been upgraded and re - designated as an AN / FPS - 66 . An AN / FPS - 26 frequency diversity height - finder radar was added during 1962 . On 31 July 1963 , the site was re - designated as NORAD ID Z - 33 . By 1966 there was an AN / FPS - 27 long - range search radar in operation there , and the AN / FPS - 66 was subsequently retired . In addition to the main facility , Klamath personnel operated one AN / FPS - 14 Gap Filler site : Over the years , the equipment at the station was upgraded or modified to improve the efficiency and accuracy of the information gathered by the radars . In 1979 Klamath came under Tactical Air Command ( TAC ) jurisdiction with the inactivation of Aerospace Defense Command and the creation of ADTAC . The 777th Radar Sq was inactivated on 30 September 1981 , and much property was turned over to the National Park Service . The FAA continued operations of the AN / FPS - 66A search radar in the old AN / FPS - 27 tower . The Klamath California radar site coverage volume was taken over by the FAA / USAF joint use site at Rainbow Ridge , CA ( J - 83A ) , operating an ARSR - 4 . The Klamath Air Force Station has been totally inactivated . In 2013 , the station is in bad repair , nature has taken over much of the site , tall brush and trees replacing areas which were once green lawns . External links .