I've been breaking up the series of the 1853 surveys and explorations to determine the most practicable route for the railway system, hoping readers would not tire of the lengthy review of the narrative journal of Isaac Stevens.
Beginning on October 7, 1853, Stevens's party (Stanley, Osgood, a disbursing agent, several travelers, Stevens and Antoine Plante, "the half-breed guide") headed out on what would be a 27-mile stretch "through a fine prairie" spotted with a couple of challenging ravines in the Valley of the Bitter Root. Stevens mentioned that the valley had many streams of clear and pure water with vast woodlands. Plante informed Stevens that on the following day they would meet with "Indians going to buffalo" - or a hunting party in our language. On the 8th, the group headed out and again traversed over patches of prairie and woodlands. Upon reaching the western edge of some wooded area, they met a group of approximately fifty Nez Percé Indians.
Here we met a band of about fifty Nez Percés Indians going to hunt. They have from 250 -300 horses, most of them splendid animals, in fine condition, and with perfectly sound backs. Women and children helped to compose the band, and babies of fifteen months old, packed in a sitting posture, rode along without fear, grasping the reins with their tiny hands. 
Wishing to converse with the Nez Percé, but not wanting to lose progress on their journey, Stevens asked if the group would be willing to go back about a mile and meet together in a more open area that would accommodate everyone. This was apparently agreeable as both groups made their way to the prairie area suggested by the guide, Antoine Plante. They were joined by a group of Coeur d’Alene, numbering about 60 men, women, and children, who were also on their way to hunt. They too had a good number of horses, 200, as well as colts. Once everyone was settled, they groups began to talk.
Stevens told the two groups about the Council at Fort Benton, and especially about the "prospect of the Blackfeet making peace with all the Indian tribes; upon the promise they had given that their war parties should be stopped; and told them that at Fort Benton and St. Mary's" he had men ready to interfere with the Blackfeet should their war parties not stop their raids. The council did not last a long time and all parties went on their separate ways shortly after a mid-day meal. Stevens and his team made their way toward the Bitter Root river and encountered two Pend d'Oreilles who joined them. They found a good camping site near the ford by which they would cross the left bank of the river on the next day. At the site they encountered a mother and daughter who had just crossed the river and pitched their lodge. They had eight pack and as many spare animals, and were on their way to join the Indians we met this morning. We gave all the Indians coffee, and the women in return gave us some cooked kamas root. It is of a dark color, small, between the pear and onion in shape, and of a sweet, agreeable flavor. The Pend d'Oreilles say that they have found four horses left by Lieutenant Sexton upon Horse plain, and promised to return them to Lieutenant Mullan. One of the Indians, an old man, knows the Bitter Root river well, but is not able to act as guide to Dr. Suckley. He thinks, however, that the father of one of his companions, also a good guide, will go; and he promises to get him and take im to the doctor. During the night one of my best riding horses was strangled, his lariat being improperly tied around his neck." 
Early in the morning of October 9th, the team crossed the ford.
 “Narrative of the Final Report of Explorations For A Route For A Pacific Railroad”, Isaac Stevens, Page 131.