Decommissioned in 1997, Oscar-Zero is now a State Historic Site. Largely constructed of #18 rebars, concrete and steel plating, Oscar-Zero took two years to complete, from 1964-1966. Southern miners were transported to North Dakota to handle digging operations for this and other such launch facilities and missile silos. Both the silos and the launch control facilities had subterranean chambers with floating floors linked to enormous shock absorbers developed by Boeing. The steel was supplied by the United States Steel Company (aka The Corporation).
Oscar-Zero's two subterranean pods were protected by thick sheathing described in a previous post, as well as by enormous blast doors, one weighing 6,000 tons, the other 13,000 tons. The missileers stationed command posts in one underground chamber (shown above), while the second chamber housed equipment. Suggestive of the many hours spent underground, the pods are adorned with murals, graffiti, and wall paper depicting more idyllic tourist destinations.
Image above: Oscar-Zero Command Station, Griggs County, North Dakota, as photographed 21.10.2011 by K. Rylance.