_Wednesday, May 23d._—At two o'clock P.M., we arrived at the ground selected for the Council, having made the march in six days. It was in one of the most beautiful spots of the Walla-Walla Valley, well wooded and with plenty of water. Ten miles distant is seen the range of the Blue Mountains, forming the southeast boundary of the great plains along the Columbia, whose waters it divides from those of Lewis river. It stretches away along the horizon until it is lost in the dim distance, where the chain unites with the Snake River Mountains. Here we found General Palmer, the Indian Agent, and Governor Stevens, with their party, who had already pitched their tents. With the latter we dined. As was proper for the highest dignitary on the ground, he had a dining room separate from his tent. An arbor had been erected near it, in which was placed a table, hastily constructed from split pine logs, smoothed off, but not very smooth. Our own preparations were made for a more permanent encampment than we have as yet had: a tent was procured for Lieutenant Gracie and myself, while the men erected for themselves huts of boughs, spreading over them pack covers. _Thursday, May 24th._—This has been an exceedingly interesting day, as about twenty-five hundred of the Nez Percé tribe have arrived. It was our first specimen of this Prairie chivalry, and it certainly realized all our conceptions of these wild warriors of the plains. Their coming was announced about ten o'clock, and going out on the plain to where a flag staff had been erected, we saw them approaching on horseback in one long line. They were almost entirely naked, gaudily painted and decorated with their wild trappings. Their plumes fluttered above them, while below, skins and trinkets and all kinds of fantastic embellishments flaunted in the sunshine. Trained from early childhood almost to live upon horseback, they sat upon their fine animals as if they were centaurs. Their horses, too, were arrayed in the most glaring finery. They were painted with such colors as formed the greatest contrast; the white being smeared with crimson in fantastic figures, and the dark colored streaked with white clay. Beads and fringes of gaudy colors were hanging from the bridles, while the plumes of eagle feathers interwoven with the mane and tail, fluttered as the breeze swept over them, and completed their wild and fantastic appearance.