My gg-grandmother was Martha Reierson Storhov or Storhof from Elverum, Hedmark Norway. Her father was Reier Pederson Storhov. She had many brothers and sisters. She married Ingebreth(Engebret or Embret) Pederson Løken. He was also from Elverum, and the Løken and Stohov farms were very close together. They had at least three sons, Peder(who came to Trempeleau county, Wisc.), Anton(my g-grandfather) who also came to Trempeleau county and Embret, who stayed in Norway. Peder and Anton took Engebretson as their last name. As for Embret, I am not sure. I know that possibly two of his sons came to America. I was able to find that there are living descendants of Embret's living in Norway today, but have not contacted them as yet.
I would love finding out more about your Riersons and Engebretsons as well. Anton's son Martin(my grandfather) married a Engebretson(no relation to him)...Sina Engebretson. Sina's father Engebret came from Sondre Land in Oppland.