Seeking descendants Petersons, from Torpa, Norway

My great-grandmother, Agnete Pedersdatter Verhaug, lived at Decorah, Iowa. Her brother, Severt, ( Feb. 5, 1836-Feb. 7, 1930), immigrated from Torpa, Norway in 1855 and lived just across the State line, at Fountain, Minnesota. His wife, Anna Johnson, was Swedish. I'd like any information about his descendants. Agnete's sister Berte, born 1830, immigrated in 1855 to Fountain, Minnesota. She married a certain Hans Peterson, and had sons Peter and Endres. Agnete's brother, also Hans, born 1828 at Torpa, immigrated in 1850 to Wiota, Wisconsin. Agnete's half brother Andrew, born 1853 at Torpa, immigrated in 1867 to Fountain(?), Minnesota, later migrated to Silverton, Oregon. His wife, Gertie, died in 1919. His daughter, Clara, married (another) Andrew Peterson, who died March 12, 1935, in Benton County, Oregon. Two of his children were Alvin, (born ca. 1928) and Andrew C. (born ca. 1929.) I'd like information about any of the above.