Center Furnace location
Contrary to what some people think, the furnace was NOT on County Road 41 south and it wasn't in the triangle, which is where most GPS coordinates on the Internet put it. There IS, however, a Center Furnace stone mounted on a concrete foundation on the triangle....it used to sit in front of one of Marquette Cement's safety monuments (the monument has since been moved).
This is "the triangle" - intersection of State Route 522/County Road 41 south. The Center furnace stone is behind that tree.
1909 Sanborn map...the public road is present-day State Route 522. But don't take my word for it - the company store and office is shown on the right....part of the company store is still standing in Superior.
Google Earth image....road is St Rt 522. The arrow pointing toward the cement plant follows County Rd 41 south. The vault for the company store is still standing....there are pictures on the Center Furnace page showing the furnace across from the company store.