Photo taken by Luke in April 2014
View this photo at 500px.com
BH Photo #282392
They kept records at golf courses. When was the earliest golf course? 1926 is the one in Osage....they are still interested in a bridge that can span the Cedar River there, so keep looking.
I really doubt this is a MOB, at least not in the ca. 1990 to present sense.
It has the potential to date to 1935. Some of the earliest welded trusses date to the 1930s, so while it would be unusual, it is not unheard of.