"Bloom County's "true" setting was known to residents of Iowa City, IA, during the strip's run. The Bloom Boarding house, which appeared as a high contrast photo within the strip, was an actual residence in Iowa City, where Breathed lived at the time." (from Search.com)

I used to live right across the street from the Bloom County Boarding House. It is on the corner of Summit and College in Iowa City. I looked for a picture to link to but came up dry.