strategic weapons assets. However the Whiteman AFB location was canceled despite the fact that specific missile and radar site locations had already been selected. Construction was actually commenced at the North Dakota and Montana sites, but only the North Dakota site was completed. Remnants of the incomplete PAR system still remain in rural Montana. Components The Safeguard system consisted of several primary components, the Perimeter Acquisition Radar, the Missile Site Radar, the Spartan missile launchers, co-located Sprint missile launchers, and Remote Sprint missile launchers. Perimeter Acquisition Radar (PAR) The PAR was a large passive electronically scanned array radar that was intended to detect incoming ballistic missile warheads as they crossed over the North Pole region. Potential targets detected by the PAR would be sent to the Missile Site Radar (MSR) and to North American Aerospace Defense Command. Two radar sites were intended to be constructed on the northern border of the United States, one in Montana and one in North Dakota. Construction was begun at both locations, but because of the ratification of the Anti-Ballistic Missile Treaty, only the site at North Dakota was completed. That site, near Cavalier, North Dakota, is now operated by the United States Space Force as Cavalier Space Force Station. Remnants of the Montana PAR site are located east of Conrad, Montana, at . Missile Site Radar (MSR) The Missile Site Radar was the control of the Safeguard system. It housed the computers and a phased array radar necessary to track and hit back at incoming ICBM warheads. The radar building itself is a pyramid structure several stories tall. Construction was begun in both Montana and North Dakota, but only the North Dakota site remains standing. The MSR complex included 30 Spartan missile launchers and 16 Sprint missile launchers. Remnants of the Montana MSR site were dismantled and buried. Remote Sprint Launchers (RSL) Remote Sprint Launchers were established around the MSR main complex in order to place missile launchers closer to their intended targets, and thus reduce the flight range to the targets. Four sites were completed, and they still remain there, around the MSR complex in Nekoma, North Dakota. RSL-1 RSL-2 RSL-3 on the National Register of Historic Places, museum RSL-4 Photo gallery Footnotes See also Sharpner's Pond Anti-Ballistic Missile Site, an incomplete radar for the Sentinel program Strategic Defense Initiative (SDI), successor to Safeguard External links Unofficial website of the Stanley R. Mickelsen