Knudt Iver Hilmen, Dakota immigrant

My great-grandfather was Knudt Hilmen (1851-1883), a homesteader near Lennox, Dakota Territory, until he was killed by lightning in 1883, a few years after he claimed his homestead. I would like to find when he came to the US and, if possible, any passenger list information. In the 1865 census for Nordre Aurdal, he is listed as the oldest son of Iver Knuds. and Marit Olsd. (He is listed as 16 years old, slightly at odds with his accepted 1851 birth date.) His parents, Iver and Marit, and two of his siblings are on the 1877 passenger list for emigrants from Oslo (Ship: Angelo, Digitalarkivet, May 25, No. 412A and No. 412B); his parents are registered under the names of Iver Knudsen Hilmen and Marit Knudsen Hilmen, but he is not with them. One family account says that he accompanied his cousin (and future wife) Ragnhild Julsen and her sister Marit Julsen, who left Oslo on June 3, 1881 (Ship: Angelo, Digitalarkivet, No. 5008A and 5008B), but I can find no evidence of his name here or anywhere between 1865 and 1883. Any help on this Valdres immigrant would be appreciated.