1. That the diluvial soil along the banks of the Ontonagon River, extending to its source, and embracing the contiguous region, which gives origin to the Monomonee River of Green Bay, and to the Wisconsin, Chippewa, and St. Croix Rivers of the Mississippi, contains very frequent, and several extraordinary masses of native, or metallic copper. But that no body of this metal, which is sufficiently extensive to become the object of profitable mining operations, has yet been found at any particular place. This conclusion is supported by the facts adduced, and, so far as theoretical aids can be relied upon, by an application of those facts to the theories of mining. A further extent of country might have been embraced, along the shores of Lake Superior, but the same remark appears applicable to it.
2. That a more intimate knowledge of the mineralogical resources of the country, may be expected to result in the discovery of valuable ores of copper, in the working of which occasional masses and veins of the native metal, may materially enhance the advantages of mining. This inference is rendered probable by the actual state of discoveries, and by the geological character of the country.
These deductions embrace all I have to submit on the mineral geography of the country, so far as regards the copper mines. Other considerations arise from the facilities which the country may present for mining—its adaptation to the purposes of agriculture—the state and disposition of the Indian tribes, and other topics which a design to commence metallurgical operations would suggest. But I have not considered it incumbent upon me to enter into details upon these subjects. It may, in brief, be remarked that the remote situation of the country does not favor the pursuit of mining. It would require the employment of a military force to protect such operations. For, whatever may be their professions, the Indian tribes of the north possess strong natural jealousies, and in situations so remote, are only to be restrained from an indulgence in malignant passions, by the fear of military chastisement.
In looking upon the southern shore of Lake Superior, the period appears distant, when the advantages flowing from a military post upon that frontier, will be produced by the ordinary progress of our settlements—for it presents but few enticements for the agriculturalist. A considerable portion of the shore is rocky, and its alluvions are, in general, of too sandy and light a character for profitable husbandry. With an elevation of six hundred and forty-one feet above the Atlantic, and drawing its waters from territories situated north of the forty-sixth degree of north latitude, Lake Superior cannot be represented as enjoying a climate favorable to the productions of the vegetable kingdom. Its forest trees are chiefly those of the fir kind, mixed with varieties of the betula, lynn, oak, and maple. Meteorological observations indicate, however, a warm summer, the average observed heat of the month of June being 69. But the climate is subject to a long and severe winter, and to sudden transitions of the summer temperature. We saw no Indian corn among the natives.
A country lacking a fertile soil, may still become a rich mining country, like the county of Cornwall in England, the Hartz Mountains in Germany, and a portion of Missouri, in our own country. But this deficiency must be compensated by the advantages of geographical position, a contiguous or redundant population, partial districts of good land, or a good market. To these, the mineral districts of Lake Superior can advance but a feeble claim, while it lies upwards of three hundred miles beyond the utmost point of our settlements, and in the occupation of savage tribes whose hostility has been so recently manifested.
Concerning the variety, importance, and extent of its latent mineral resources, I think little doubt can remain. Every fact which has been noticed tends to strengthen the belief that future observations will indicate extensive mines upon its shores, and render it an attractive field of mineralogical discovery. In the event of mining operations, the facilities of a ready transportation of the crude ores to the Sault de Ste. Marie, will point out that place as uniting, with a commanding geographical position, superior advantages for the reduction of the ores, and the general facilities of commerce. At this place, a fall of twenty-two feet, in the river, in the distance of half a mile, creates sufficient power to drive hydraulic works to any extent; while the surrounding country is such as to admit of an agricultural settlement.
I accompany this report with a geological sketch of a vertical section of the left bank of the Mississippi at St. Peter's, embracing a formation of native copper. This formation was first noticed by the officers of the garrison, who directed the quarrying of stone at this spot. The masses of copper found are small, none exceeding a pound in weight.
I have the honor to be, sir,
Very respectfully,
Your obedient servant,
HENRY R. SCHOOLCRAFT.