There was massive flooding in Pennsylvania in the summer of 1915, called the worst flood on record. Perhaps it was the low lying holes that went out of service, and the higher ones remained in play. Who knows.
Sven,
I'm basing my guess on the land that Donald Ross used when he expanded the course back to 18 holes in 1922, opening in 1924, as he abandoned the holes drawn on that map in the Northeast Corner (as the map is oriented).
Incidentally, this 1924 article I earlier posted to your "Reunderstanding Ross" thread mentions the par threes and if one is not careful it might be interpreted that the 14th (aka "Little Tilly") is a new Ross hole. However, I'm understanding that Tillinghast wrote a promotional pamphlet published in 1917 called "Planning A Golf Course" that included drawings and descriptions of holes he created and/or reconstructed that includes a drawing of the "2nd Hole" at Bedford Springs that has been named "Little Tilly" over the years so I think we've filled in the pieces here.
The only other thing I'd mention that I find interesting to our dialogue here is that if that's Barker's 18-hole routing, which I think we both now believe, is that it was done on a topographical map as I suspected, although the topo lines on our copy from the club's website are virtually invisible.

