Photo caption reads "Chicago Commercial Club members posing in front of the Snoqualmie Falls Power Company sign, Snoqualmie, Washington, March, 1901"

Are those some sort of bus bars coming out of the small building into the substation???

Update: I believe this building may have covered the shaft where the cables from the generators came up to the transformer house (the building on the right). Water was diverted down to the generators, 200 feet below the river in a cavern excavated out of the rock, and discharged at the base of snoqualmie falls, thus no dam was needed.

This station is still generating power and is now owned by Puget Sound Energy