I am tracking a Rhoda/Ragnhild who resided in the Perry Dane County area. Several of her children had biographies written, and she is sometimes described as the former Ragnhild Halvorson, and sometimes she's referenced as the former Ragnhild Gonstad. I'm thinking that your Gonstad, Halvor Halvorson is probably her father.
Ragnhild was born in Norway in 1838, and supposedly came to America around 1851. By 1860 she is married to L. M. Anderson, so I cant find her as a single woman in any census records. What do you think - does this look like a likely match?
I've been confused about why she was sometimes referenced as a Gonstad and sometimes as a Halvorson. Is your guy named Halvor Gonstad, but sometimes used Halvor Halvorson?