H. O. Fossum

I am looking for any information on H. O. Fossum. He lived in Pierce County, ND (Rugby, ND area) on May 16, 1904. Does anyone know when he came to America from Norway, or from where in Norway? I am trying to find out as much as I can about H. O. Fossum as he signed the Naturalization document of Mike Anderson who I think was my grandfather (Melkor Anderson Oien/Oyen who came from the Rendalen region of Norway in Dec 1891). If I find out more about H. O. Fossum, it may lead me to further information on my grandfather. Thanks