Location: On top of Flagstaff Mtn (elevation 4,255 ft) app. 3.5 miles west of Northport, Stevens County, WA.

Findings of Fact report that the site consisted of 50.15 acres acquired in 1958 by leases from several private parties, license from Stevens County for road access, and memorandum of understanding from the Dept of Agriculture.

A radar station was constructed and completed in 1959, consisting of road access, control building, radar tower, sanitary latrine, security fence, installation of a 4,000-gallon fuel storage tank, plus all associated equipment and improvements needed to operate the radar station.

The unmanned annex supported the primary installation at Colville Air Force Station. It was deactivated by the Air Force on 1 September 1960 and declared excess in October. Work was contracted in September 1961 for the removal of the security fence, fuel storage tank, dismantling of the concrete building to floor elevation, removing the sanitary latrine and pushing all remaining masonry into nearby depressions. The road, sidewalk, and storm drainage were left in place.

The report also states the 1988 site inspection revealed the only visible remains were the concrete foundations for the tower, as the control building slab and underground fuel tank were apparently removed.