The caption under a photograph (much like the one above) in the "OCEAN" (Oregon College of Education Alumni News) dated March 1975, contains the following ~

"Millstones which were placed on a pedestal behind the old south wing of Campbell Hall in 1925 still stand in nearly the same place.
The hand-wrought stones were shaped by Medis Vanderpool, a surveyor who established a grist mill south of Monmouth in about 1850."