The Pictured Rocks are situated between the copper regions and the ancient portage, which has been recently superseded by a canal opening navigation for the largest vessels from Lake Huron to Lake Superior. They lie in the centre of the long indentation, which, sweeping from Keweenaw Peninsula eastward to White Fish Point, forms the coast most distant from the northern shores of the lake. Here the cliffs have been exposed through unnumbered ages to the waves under the action of northerly winds; while a contemporaneous upheaval, prolonged probably through vast periods of time, has contributed no unimportant share in the operations by which their striking forms have been produced. Beyond those the voyager comes once more on rocky cliffs in the vicinity of Marquette: so named after the Jesuit missionary by whom the upper waters of the Mississippi were first reached two centuries ago, in 1673. Important changes have been wrought in the interval. Mineral treasures, undreamt of by the ancient miners, are now rewarding the industry of the Indians’ supplanters. The iron period, with its fully developed civilisation, is invading those forest tracks; and when I first visited Marquette in 1855, on the bold trappean rocks which form the landing, abraded and scratched with the glacial action of a long superseded era, were piled the rich products of the “Jackson Iron Mountain,” which rears its bold outline at a distance of twelve miles from the shore. Immediately to the north of this point the promontory of Presque Isle presents in some respects a striking contrast to the Pictured Rocks; though, like them, also indented and hollowed out into detached masses, and pierced with the wave-worn caverns of older levels of shore and lake. Here the water-worn sandstone and the igneous rocks overlie or intermingle with each other in picturesque confusion: the symbol, as it were, of the transition between the copper and iron eras. For it is just at Presque Isle that the crystalline schists, with their intermingling masses of trappean and quartz rocks, richly impregnated with the specular and magnetic oxide of iron, pass into the granite and sandstone rocks, which intervene between the ferriferous formations and the copper-bearing traps of Keweenaw Point. Beyond this, the rich copper-bearing region of the Keweenaw Peninsula stretches far into the lake, traversed in a south-westerly direction by magnificent cliffs of trappean rocks, presenting their perpendicular sides to the south-east, and covered even amid the rocky débris with ancient forest-trees. In this igneous rock are found the copper veins, which in recent years have conferred such great commercial value on the district of Michigan; and there I not only witnessed extensive mining operations in progress, but have investigated evidences of the ancient miners’ labours which prove the prolonged practice there, at some remote period, of native metallurgic arts.