The whole route from Walla Walla to Fort Boise (250 miles) is being settled with either farmers or miners. First comes Grande Roude Valley, containing some inviting agricultural land, where there is a considerable settlement. Next, Powder River. On this river the gold mines have attracted many people and a large share of the emigration this fall. Auburn, on Powder River, twenty-five miles west of the emigrant road, contains now 300 houses. Next comes the mines on Burnt River, and lastly the recently discovered and very inviting gold mines on Boise River. I am satisfied from personal inquiry of reliable persons whom I met in Portland that there have been discovered such attractive mines on that river that there can be no doubt there will be a rush of thousands in that direction next spring. I append to this letter one newspaper statement on this subject, which I have reason to believe is a fair sample of the well-vouched reports from Boise River.