The largest room was the diesel laboratories, which tested various devices and fuel additives to make it safer to mine underground with diesel trucks and other machinery, such as at White Pine Mine, Michigan.
The roof compromised, rain water rolls down the main stairway.
A window for light and air pokes above the big arch in the hallway. Most of the interior ceilings were broad brick archways.
A bumper sticker with the usual tagline. Note the detail on the radiator!
The big door at the bottom of the concentrator was where a tram once connected to lower the (pre-) processed ore into the river valley, where the railroad was. It’s unclear whether this ever connected directly to Eureka’s Sunnyside mill, although it’s possible.
The bottom of the stairs leading from the work floor to the cafeteria.
Presumably, in a nuclear blast the antenna would be blown flat and pop back up, allowing communication even after a near-direct hit.
The first floor hallway between conference rooms and the diesel lab at the center of the facility
An insurance office.
The old truck scale sits in the middle of what was Nettleton Avenue Slip.