Terry, send an email to the SW Wisconsin Room at UW Platteville. Request the obit from them. There will be a small charge (my last one was $3.00), they'll bill you when they send the obit (if they find it). Make sure you help them out and tell them where he was living when he died so that they can check the most logical newspaper.http://www.uwplatt.edu/library/swwis/
But before you do, can I assume you've checked with the Grant County Genealogical Society for his burial records (which would hopefully give you his death date) and/or Findagrave? In case you didn't, I just looked at Findagrave and he's not listed in Grant County. In fact, the most recent Borah burial in the county is from 1939. Of course, these listings do not normally include unmarked graves.