I grew up in Mellen and spent lots of time at the two quarries near Loon Lake, where my family had a cabin. I still go there for the summers. The waste piles of black gabbro have been cleaned out, first to use the large blocks for piers in Lake Superior and then smaller pieces ground up to use in artificial granite countertops. I don't know much about the Effenberger brothers, but Joe Barabe is Mayor of Mellen and has done extensive historical research. He has published two books on the history of Mellen which probably contain some information. You could write him at: Joe Barabe, Mellen, WI 54546.