|Humboldt, MN Great Northern depot looking SW (June 1969)|
Source: Great Northern Railway Historical Society
I see it was two-stories in the main part of the building, which leads me to believe it had living quarters over the offices for the depot agent, (and his family, if he had one.) The attached single-storey portion is probably the freight office.
I did a little digging online and found that one of the those families were the Merck's.
Anthony "Tony" spent his entire adult life employed by the Great Northern Railway at various locations in the Red River Valley area of North Dakota and Minnesota which included Humboldt, Minnesota... - Anthony Merck, Red River Valley website
|Margaret (Jerome) Merck, visiting husband Tony in the Humboldt Depot...|
Source: Merck Family website
Thanks to William Ash for the heads-up on this photograph.