Walla Walla.
Lewis and Clark had ran into the Walla Walla tribe in early October of 1805.  There chief is Yelleppit. When they first met Lewis and Clark were in a hurry and didn't want to stay with them at first. But then Yelleppit managed to promise for the captains return to his village on their way back.

The Walla Walla live about 12 miles away from the junction of the Snake and Colombia rivers of present day Washington. There were 15 lodges in the Walla Walla camp. The Walla Walla had also welcomed the Americans very nicely to stay in their camp. The two groups could easily know what each other was saying cause of a Shoshone woman that the Walla Walla had captured.

Yelleppit loved the presence of his foreign friends mainly because of the southern trade  for goods such as kettles. To make sure that the Americans and the Walla Walla would stay friends, Yelleppit awarded a white horse to Clark.

Wishram
They lived near the Columbian River, later know as Dalles. The area was shared by two tribes, one known as the Wasco and the other Wishram. The Wishram were on the North side and the Wasco were on the South side.

Around this area there were trades happening. The main trades happened in Nixluidix. When Lewis and Clark went to Nixluidix in October 1805, they found 20 large houses. In each house there were three families of the Wishram Indians. They had arrived in mid April which is around the main trading times and there was a really big school of fish swimming up stream. Clark recorded 107 stacks of salmon, and estimated their weight to be over 10,000 lbs.

The Wishram tribe traded most of their salmon with the Walla Walla, the Nez Perces, and the Yakimas Indians. This is one of the many ways they had encountered the other  tribes. The other tribes had brought animal skins, horses and buffalo meat.

Oto

The Oto Indians were with the Southern Sioux tribes and they lived along the Missouri River. For food they hunted buffalo and planted crops.
A very big small pox infection got out and it had depleted most of their members. And then they joined up with the Missouri Indians and they then got about 250 people.
Lewis and Clark had reached their town in about July 1804. When they came most of the tribe was out hunting. While they were hunting the Corps sent out two men to go look for the hunting men. After they could not find them they decided to go more up the river.
On August 2, some Oto Indians came to the Corps camp site, this camp site was named Council Bluff by Clark himself.
On August 3, with a great ceremony, Lewis and Clark had the first annual meeting between the representatives of the united states and western Indians.