Norwegian Immigrants to America

My grandmother, Anna Maria, arrived in Alpena, Michigan sometime in the early 1880's. She was about 12 at the time and was an orphan. She came over on a Norwegian ship filled with Norwegian immigrants who settled in Alpena. I don't know the name of the ship, but I do know the name of the skipper. His name was Erickson. That is the surname my grandmother assumed. Is there anyone out there in Internet land who may know something about that ship of Norwegians. Most of them are buried in the Norwegian Lutheran Cemetary in Alpena. Peter M. olsen