The original water tanks erected by the SVRy of the square house type now at McEwen, and were located about 12 miles apart. Not long ago I saw reference to a tank between Boulder Gorge and Salisbury, with a name I was not familiar with. (I don't immediately recall the name.) Anyway, when the larger locomotives arrived the square tanks were replaced with the larger octagonal tanks, spaced further apart. Some of the square tanks (the tanks were actually round, only the house was square) were transfered to the Oregon Lumber Co. for use on the Middle Fork line. Both of the tanks currently on the property are believed to have gone this route, although no records exist of the transactions. The tank at McEwen was indeed last used as the municiple storage for Bates, but I don't know if it did a stint on the OLCo line in the interem. I was not involved in recovering the tank at Sumpter, but I believe it came from the Middle Fork.
On the subject of trivia, I don't think I saw reference to the tanks at Johnson's Jumpoff and Telephone Springs. These were very early tanks and might not have been there in 1916. They were located on either side of Larch, about half way up the hill.