Subject: Lake Superior, Michigan
Period: 1847 (dated)
Publication: 
Color: Hand Color
Size:
22.3 x 13.5 inches
56.6 x 34.3 cm
This is a very detailed geological map that covers the region from Portage Lake to the tip of the point and also shows Manitou Island.  A color-coded key locates geological units including sandstone, conglomerate, trap and jasper.  The legend locates minerals, active and abandoned mines, and furnaces.  A scale below title converts chains to miles.  Fancy title lettering.
References: Karpinski (MI) #758b; cf. Marcou & Marcou #362
Condition: B+
There is some light toning along the folds and a few small spots in the image, else very good.  Issued folding.