Summary Narrative of an Exploratory Expedition to the Sources of the Mississippi River, in 1820 / Resumed and Completed, by the Discovery of its Origin in Itasca Lake, in 1832

by Henry Rowe Schoolcraft

III.

Copy of a letter from Gov. Lewis Cass to Hon. John C. Calhoun, Secretary of War, dated

Detroit, September 20, 1820.

Sir: In examining the state of our topographical knowledge, respecting that portion of the Northwestern frontier over which we have recently passed, it occurs to me that there are several points which require further examination, and which might be explored without any additional expense to the United States.

The general result of the observations made by Capt. Douglass, will be submitted to you as soon as it can be prepared. And I believe he will also complete a map of the extensive route we have taken, and embracing the whole of the United States, bounded by the Upper Lakes and by the waters of the Mississippi, and extending as far south as Rock Island and the southern extremities of Lakes Michigan and Erie. The materials in his possession are sufficient for such an outline, and he is every way competent to complete it. But there are several important streams, respecting which it is desirable to procure more accurate information than can be obtained from the vague and contradictory relations of Indians and Indian traders. The progress of our geographical knowledge has not kept pace with the extension of our territory, nor with the enterprise of our traders. But I trust the accurate observations of Captain Douglass will render a resort to the old French maps for information respecting our own country entirely unnecessary.

I beg leave to propose to you, whether it would not be proper to direct exploring parties to proceed from several of our frontier posts into the interior of the country, and to make such observations as might lead to a correct topographical delineation of it. An intelligent officer, with eight or ten men, in a canoe, would be adequate to this object. He would require nothing more than a compass to ascertain his course, for it is not to be expected that correct astronomical observations could be taken. In ascending or descending streams, he should enter in a journal every course which he pursues, and the length of time observed by a watch. He should occasionally ascertain the velocity of his canoe, by measuring a short distance upon the bank, and should also enter in his journal his supposed rate of travelling. This, whenever it is possible, should be checked by the distance as estimated by traders and travellers. By a comparison of these data, and by a little experience, he would soon be enabled to ascertain with sufficient precision, the length of each course, and to furnish materials for combination, which would eventually exhibit a perfect view of the country. I do not know any additional expense which it would be necessary to encounter. An ordinary compass is not worth taking into consideration. A necessary supply of provisions, a small quantity of powder, lead, and tobacco, to present occasionally to the Indians, and a little medicine, are all the articles which would require particular attention. Officers employed upon such services should be directed to observe the natural appearances of the country; its soil, timber, and productions; its general face and character; the height, direction, and composition of its hills; the number, size, rapidity, &c., of its streams; its geological structure and mineralogical products; and any facts which may enable the public to appreciate its importance in the scale of territorial acquisitions, or which may serve to enlarge the sphere of national science.

It is not to be expected that officers detached upon the duties can enter into the detail of such subjects in a manner which their importance would render desirable. But the most superficial observer may add something to the general stock; and to point their inquiries to specific objects, may be the means of eliciting facts, which in other hands may lead to important results. The most important tributary stream of the Upper Mississippi is the Saint Peter's. The commanding officer at the mouth of that river might be directed to form an expedition for exploring it.

It is the opinion of Captain Douglass, and it is strongly fortified by my personal observation, and by the opinion of others, that Lieut. Talcott, of the Engineers, now at the Council Bluffs, would conduct a party upon this duty in a very satisfactory manner. He might ascend the St. Peter's to its source, and from thence cross over to the Red River, and descend the stream to the 49th parallel of latitude, with directions to take the necessary observations upon so important a point.[ [200] Thence up that branch of the Red River, interlocking with the nearest water of the Mississippi, and down this river to Leech Lake. From this lake, there is an easy communication to the River de Corbeau, which he could descend to the Mississippi, and thence to St. Peter's.[ [201]

The St. Croix and Chippewa Rivers, entering the Mississippi above and below the Falls of St. Anthony, might, in like manner, be explored by parties from the same post.[A] The former interlocks with the Mauvais and Brulé Rivers, but a descent into Lake Superior would not probably be considered expedient, so that the party would necessarily ascend and descend the same stream.[ [202]

The Chippewa interlocks with the Montreal and Wisconsin Rivers, and consequently the same party could ascend the former and descend the latter stream.

A party from Green Bay might explore Rocky River from its source to its mouth.

A correct examination of Green Bay and of the Menomonie River might be made from the same post.

The St. Joseph and Grand River, of this peninsula, could be examined by parties detached from Chicago.

It is desirable, also, to explore the Grand Traverse Bay, about sixty miles south of Michilimackinac, on the east coast of Lake Michigan.

These are all the points which require particular examination. Observations made in the manner I have suggested, and connected with those already taken by Captain Douglass, would furnish ample materials for a correct chart of the country.

It is with this view that it might be proper, should you approve the plan I have submitted to you, to direct, that the reports of the officers should be transmitted to Captain Douglass, by whom they will be incorporated with his own observations, and will appear in a form best calculated to promote the views which you entertain upon the important subject of the internal geography of our country.