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 Authority of the United States.

WITH APPENDICES,

COMPRISING THE

ORIGINAL REPORT ON THE COPPER MINES OF LAKE SUPERIOR, and obsERVATIONS
ON THE GEOLOGY OF THE LAKE basins, and THE SUMMIT OF THE MISSISSIPPI;

TOGETHER WITH

ALL THE OFFICIAL REPORTS AND SCIENTIFIC PAPERS OF BOTH EXPEDITIONS.

Entered according to the Act of Congress, in the year 1854, by

LIPPINCOTT, GRAMBO, AND CO.,

in the Office of the Clerk of the District Court of the United States, in and for the Eastern District of Pennsylvania.

F597 53

[ORIGINAL DEDICATION.]

TO THE

HON. JOHN C. CALHOUN,

SECRETARY OF WAR.

SIR: Allow me to inscribe to you the following Journals, as an illustration of my several reports on the mineral geography of the regions visited by the recent Expedition under Governor Cass.

I beg you will consider it, not only as a proof of my anxiety to be serviceable in the station occupied, but also as a tribute of individual respect for those exertions which have been made, during your administration of the War Department, to develop the physical character and resources of all parts of our Western country; for the patronage it has extended to the cause of geographical science; for the protection it has afforded to a vere extensive line of frontier settlements by stretching as, cordon of military posts around them; and for the it has bestowed on one of the humblest cultivato natural science.

ALBANY, 1821.

was

g all

riginal