Thanks for the reply. Garretson is a town in South Dakota, USA where the family emigrated to.
I was confused by the naming as well, and don't know if the parent information is correct, which is why I'm trying to track it down. Some family information just lists him as Amund Bru. Others, Amund Bru Sandven, others Amund Bru Sandven Edmundson. I figured the Edmundson is actually just his children being Edmundson and that being applied backwards.
I thought Bru was the farm name and that his last name was just taking the farm and that his father might actually be Mikjell.