624 OREGON. 
northward about Fort Colville, there are some spots favourable for 
cultivation, but they are very small. In general it is an indifferent 
grazing country, where in some parts, with a sufficiently wide range, 
horses may be profitably raised. It should be understood, however, 
that the unproductiveness is in general a result of the dryness of the 
climate; and where irrigation is practicable the land will often yield 
abundantly. The plains south of Fort Colville are of a most unpro- 
mising rocky character. Ascending the Columbia, about two hundred 
and fifty miles from its mouth, there is what has been called “the 
last tree,” as it is literally the last on its banks for a long distance. 
It affords a good index of the dry climate, and shows that it is increas- 
ingly dry as we go eastward towards the summit of the mountains. 
Beyond the Blue Range, there are wide plains and rolling prairies, 
and some districts of high mountains. But it is mostly a dry waste, 
yielding little besides wormwood and some equally profitless plants, 
and those sparingly. 
The rivers through both of these sections lie in channels, often one 
or two thousand feet below the general level of the plains. Dr. 
Pickering informed me that this is the general character of the 
Columbia north of Wallawalla, and also of the Kooskooski River, 
which have in many parts beds two thousand feet deep. A remark- 
able valley, two to three miles wide, resembling one of these river 
gorges, intersects the bed of the Columbia below Fort Colville, (see 
map of Oregon, by the Expedition.) It commences about thirty 
miles east of Okanagan, and after a somewhat curving course of one 
hundred and fifty miles, meets the river again seventy-five miles 
above its junction with the Snake River. It is called the Grande 
Coulée. Precipitous walls, generally of rock, and eight hundred to 
one thousand feet high, bound it on either side. Rocky peaks, some 
of them as high as the walls, partially obstruct the northern entrance. 
Its bed to the southward is strewed with granite boulders, which 
came from the northern portion of the gorge. 
We might dwell farther upon the features of the Columbia in this 
section, its ‘ Cascades,” “ Falls,” and “Grand Rapids ;” but they did 
not come within the observation of the writer, and are already de- 
scribed in the Narrative of the Expedition by Captain Wilkes. 
Passing beyond Oregon, either to the north or south, the country 
does not improve in its agricultural resources. North of Oregon the 
country is poor, and is especially difficult of cultivation on account of 
the severity of the climate. The Cascade Range borders the coast, and 
