I knew Severt John Strand and am related to him. I called him "Uncle Severt," although the word Uncle may have just been a term of endearment, as I think he might have been my grandfather's cousin. I grew up in Sanborn County, South Dakota. When I was a kid (in the late 1970s and early 1980s) we used to visit Uncle Severt at his farm. He was a very kind man. To my knowledge, he never married.
Sigurd Strand and his wife Margit had a farm nearby. I am not exactly sure how they were related to Severt. Margit passed away just a few years ago at the age of 101.
Oscar Strand was my great-grandfather. His son Douglas Strand was my grandfather.
When I was a kid I remember Severt used to say the Lord's prayer in Norwegian before dinner. He had a really old black labrador dog and a beautiful old farm right near a creek. Severt is now buried in a small family cemetery just up the hill from his farm.
I realize I am not providing precise information on the exact family relationships. If you would like more specifics on how the above people were related, please let me know and I will ask my mother.
Good luck with your search!