The circular object in the middle of the lower left quarter of the photo is the covered water storage reservoir also seen at the
aborted Montana PAR site (lower right).
04921 :
A closer high altitude photo showing southern half of the MSR site after restoration (1997).
The building just to the right of center looks very much like the
H building (named for its shape) at the Mickelsen MSR complex in North Dakota.
At the Mickelsen complex, the Corps of Engineers used the H building as their headquarters during construction. After the site was activated, the H building was used for general office space (housing office, re-enlistment office, print/copy service, etc.).
04907 :
The covered water storage reservoir (2004).