There is a Herke Cornelius Joffer (1883-1948) whose second marriage put him in our Plooster/Beukelman family genealogy.
However, I do not have his parents' names or anything more than his birthplace was in the Netherlands.
He came from the Emery/Parker S.D. area and moved to Corsica S.D.
He had 3 brothers and 1 sister who I think were George, Clarence and Jake. The sister may have been a Mrs. Nieswaag.