In 1920, Ole and Mari Finnestad's great grandson, Ole Alfred Knutson was still residing at the Watertown State Hospital. (Listed as patient #29).
Apparently the census taker either didn't receive accurate information, or the patient didn't know since I note it indicates both Ole's mother and father were born in Illinois. Both parents Elizabeth and Ole Andreas Knutson were born in Norway.
I've attempted to locate the 1930 census for Ole but was unable to locate one.
The Rock Island county records do indicate he died on January 8, 1934 in East Moline, so he was apparently a patient until he died at the age of 51 - 2 months shy of his 52nd birthday.