Cassie,
I wish I could help, if you can get any information on your father's family I have alot of info going back. This family was originally out of NY, then PA, then some went to Illinois. An Eliza Engelhaupt was the second wife of my 4th Great Grandfather.
Many of the families are related to each other. See if you can check out the 1930 census in the area that your father lived and see if any Englehaupts were in the area, this may help you go back or help you figure out who is mother might have been.
We had some family move to Oregon, but I don't know why?
Let me know if you get any new information.
Sincerely,
Terry