In the course of the night the rain had commenced and Lieutenant Gracie and I were striving to keep dry and sleep under the little tent of pack covers we had hastily erected, when we were startled from our first slumbers by a terrific yell. It may be imagined that it did not take us many seconds to be on our feet, with our pistols ready for, what we supposed, was an attack. Looking out, however, in the dark night, every thing seemed quiet on the prairie. The animals were grazing around, and not an Indian to be seen. Upon inquiry, we discovered that the disturbance had been caused by one of the soldiers finding a large snake in bed with him. The reptile probably did not like the rain, and therefore crawled under the soldier's blanket for warmth. What species it was we did not learn, for the snake, disgusted with his inhospitable reception, glided away, and the soldier did not detain him to make any enquiries about his parentage. _Tuesday, May 22d._—Our course this morning was through the same desolate country, until we struck the Umatilla, a beautiful stream fringed with trees. About ten o'clock we came upon a party of ten soldiers of the 4th Infantry, who were encamped by the river. They had been sent out from the Dalles a week before, under the command of a corporal, in pursuit of some Indian murderers, in finding whom, however, they had been successful. As Lieutenant Gracie had been directed, in event of meeting them, to add them to his command, their camp was broken up and they marched on with us, making the number of soldiers forty-seven. Towards evening our guide announced that we were but a few miles from the valley which was the residence of the Cayuse tribe. Lieutenant Gracie, therefore, sent on the soldiers under command of a sergeant to find a camping place for the night, while we, under the guidance of Mr. Cut-mouth John, struck across the country to visit his countrymen. We found their lodges in a beautiful, well-watered valley, which I am not surprised they are unwilling to give up. They are, however, much diminished in numbers, and did not seem to amount to more than two hundred. We went into several of their lodges, and although they are notoriously the most unfriendly tribe to the whites among all the Indians in this region, of which we afterwards had some strong evidences, yet on this occasion they received us well and showed no feelings but those of cordiality. After leaving them, we returned to the trail, and riding on about five miles, found our party encamped by the Umatilla.