The Stanley R. Mickelsen Safeguard complex in Nekoma, North Dakota, or locally known as the Pyramid, was constructed in the 1970s. It was built to defend the Minuteman ICBM or Intercontinental Ballistic Missile silos at the Grand Forks Air Force Base, located roughly 90 miles away.  

The Pyramid was named after Lieutenant General Stanley R. Mickelsen, who was a former commanding general of the U.S. Army Air Defense Command. The complex featured various radar systems, its own fleet of Spartan and Sprint missiles, along with the ability to command over 50 Sprint missiles located in four remote Sprint launch sites.

The Pyramid did not last very long, though. By long, I mean one day…According to sources, it reached full operational status on Oct 1, 1975, and Congress voted to deactivate it on Oct 2, 1975. It would close fully in 1976. 

It would sit idle for many years, until it came up for auction and was sold in 2012. It would then go on to change hands again in 2020.