What about this WWI registration.http://search.ancestry.com/iexec?htx=View&r=an&dbid=...
Marinus Nielsen, born Feb 5th 1894, Skovsgaard St(ation),
June 1917 living in Fenton, Kossuth, Iowa.
Census 1940 in your tree, he is living in Seneca, Kossuth, Iowa.
Skovsgaard St(ation) is a part of Oester Svenstrup parish,Oester Han, Hjoerring in Denmark.
I have searched for his birth and conformation there, but without luck.
But anyway it could be an indication that he is from that part of Denmark.