This appears to be the first mention of the Cayuse tribe, later so prominent in Oregon history. Their language was unlike that of the Wallawalla, so that they are classified as Waülatpuans. Their habitat was the Wallawalla Valley, and south and east of the great bend of the Columbia. Their herds of horses were so numerous that “cayuse” has become a generic term for Indian ponies. These Indians constituted the largest and most powerful tribe of Eastern Oregon. Among them the American Board founded a mission, and it was this tribe that perpetrated the Whitman massacre of 1847. Broken in spirit and numbers by the settlers’ avenging warfare, five chiefs were in 1850 surrendered for trial and executed. Five years later, the Cayuse formally ceded their lands and retired to the Umatilla reservation, where three hundred and ninety-one are now (1902) reported. They have abandoned their language for that of the Wallawalla.—ED. Footnote 39: Thompson records (July 9, 1811) “½ a mile to the Junction of the Shawpatin [Snake] River with this the Columbia, here I erected a small Pole, with a half Sheet of Paper well tied about it, with these words on it—Know hereby that this country is claimed by Great Britain as part of its Territories, & that the N W Company of Merchants from Canada, finding the Factory for this People inconvenient for them, do intend to erect a Factory in this Place for the Commerce of the Country around. D. Thompson.”—_Henry-Thompson Journals_, p. 748.—ED. Footnote 40: Ross is here inaccurate. The Snake River was called the Lewis; but to the Columbia above the fork, the explorers never applied the name of Clark—that was given to the large northern branch still called Clark’s Fork of the Columbia, upon whose upper waters the explorers rested when crossing the mountains.—ED. Footnote 41: The Yakima (Eyakema) River enters the Columbia from the east, about ten miles above the Snake. It is a large tributary, draining the eastern slope of the Cascade Range. Lewis and Clark called it the Tapteet. The Northern Pacific Railway follows the valley of the Yakima for some distance.—ED. Footnote 42: It was on the return journey (May 1, 1806) that three Wallawalla overtook Lewis and Clark, with a steel trap which they had travelled a day’s journey to restore.—ED. Footnote 43: This is the Gualquil Rapid, one hundred and ten miles above the mouth of Snake River. The Kewaughtohenemachs are mentioned only by Ross; they were probably a Pisquow tribe. For a description of the Columbia above the entrance of the Snake, see Symons, _Upper Columbia River_ (Washington, 1882.)—ED. Footnote 44: