THE DISCOVERY OF THE SOURCE OF THE COLUMBIA RIVER
Settlement of the Oregon boundary dispute by the treaty of 1846 on the basis of the forty-ninth parallel of North latitude from the Lake of the Woods west to Georgia strait included a remarkable coincidence, in that such a line at its western end actually divided the watershed of the Fraser river from that of Puget Sound—using the last term broadly. This was as it should be by reason of the journey of Alex. MacKenzie in 1792, and the explorations of Simon Fraser in 1806 and the prior occupancy of the watershed of the Fraser by British tradings posts or forts. The United States had acquired any Spanish rights of discovery of the mouth of that river by Elisa in 1790 or 1791, but did not press that claim.
On the other hand the United States asserted a right to the entire basin of the Columbia river because of the first entrance of its mouth by Capt. Gray in 1792 and the explorations of Lewis and Clark in 1805-6, but waived such right to that half of the river, which lies north of the forty-ninth parallel. This also was just because an Englishman, David Thompson, had first found and explored that part of the river. This fact received little or no attention in the diplomatic controversy, and may also be called a remarkable coincidence. But in losing this part of the basin of the Columbia, the United States obtained all of the Puget Sound country, which Capt. Geo. Vancouver had discovered and explored and mapped in 1792.
These remarks serve to introduce the document now presented, namely, a cotemporaneously written account by David Thompson of his discovery of the source of the Columbia in 1807. The mss. transcript of this document has come to the writer through the courtesies of the Archives Department of the Canadian Government and a friend who is much interested in such research, Mr. John A. Chisholm, of Canada.
