Do you have any info about who built the stone buildings in/near Claremont CA that were built around 1910?

Question

These buildings include the Pitzer House, but I am not so interested in the buildings in Russian Village. The derelict ranch buildings at Baseline and Monte Vista are of interest, as well as the house recently revovated on baseline near Towne, the house at Baseline and Mountain, and the vacant house just below the 210 freeway on the east side of Indian Hill.
To me, these buildings seem to have a constitent, unusual style of incorporation of boulders such that a diagonal, almost plaid effect is generated. I am guessing that the same designer, stoneworker, or artisan may be involved in each one. One house was designed by Orr, but I have no information about whether or not Orr used a stonemason.

Answer 1

Robert Orr was the architect for the Pitzer House:

http://history.acusd.edu/dd/images/ArtsCrafts/Pages/ARCH28.html

(I love strolling down Monte Vista Avenue in Piedmont to check out the awesome ranchers & gardens there.)