Jacob C. Finstad arrived in the US in 1871 (according to the 1900, 1910 and 1920 census). He lived in Iowa from at least 1880-1889, then Washington (at least 1892-1896) and then Idaho (at least 1900 until his death). His wife was Eva Louise Spriggs. They probably married in Iowa 1881-1882.
Many online trees show his father as Casper Finstad. I doubt seriously that the family actually came from Bergen.
I think this family could be correct, but I don't have time to check it right now:http://digitalarkivet.no/cgi-win/webcens.exe?slag=visbase&am...