Alturas, CA utility? (0879)

An unlabeled mystery building in Alturas, CA. The art deco architecture, the symbols at the upper level, the very tall windows, the insides that looked like a machine room (see nearby picture), and the structure of the front grounds and wall (not photographed, see satellite) suggested that it was a building for some sort of public utility built in the 30's. The tanks on the left are on a separate property, and there are no major utility wires nearby to provide any hints, so I couldn't figure out what. The lower structure along the front is clearly a later addition. Searching the web came up with nothing.