EARLY HISTORY OF OREGON. 269 



The United States of America had in the meantime not 

 remained inattentive to their own future commercial interests 

 in this quarter, as they had dispatched from the southern side 

 an exploring party across the Rocky Mountains almost imme- 

 diately after their purchase of Lousiana in 1803. On this oc- 

 casion Mr. Jefferson, then President of the United States, com- 

 missioned Captains Lewis and Clarke " to explore the River 

 Missouri and its principal branches to their sources, and then 

 to seek and trace to its termination in the Pacific, some 

 stream, whether the Columbia, the Oregon, the Colorado, or 

 any other which might offer the most direct and practicable 

 water-communication across the continent for the purpose of 

 commerce." The party succeeded in passing the Rocky 

 Mountains towards the end of September, in 1805, and after 

 following, by the advice of their native guides, the Kooskookee 

 River, which they reached in latitude 43° 34' 00", to its 

 junction with the principal southern tributary of the Great 

 River of the West, they gave the name of Lewis to this 

 tributary. Having in seven days afterwards reached the 

 main stream, they traced it down to the Pacific Ocean, where 

 it was found to empty itself in latitude 46° 18' 00" north. 

 They thus identified the Oregon, or Great River of the West 

 of Carver, with the river to whose outlet Captain Grey had 

 given the name of his vessel, the Columbia, in 1792, and 

 having passed the winter among the Clatsop Indians in an 

 encampment on the south side of the river, not very far from 

 its mouth, which they called Fort Clatsop, they commenced 

 with the approach of spring the ascent of the Columbia on 

 their return homeward. After reaching the Kooskookee, they 

 pursued a course eastward, till they arrived at a stream, to 

 which they gave the name of Clarke, as considering it to be the 

 upper part of the main river which they had previously called 



