The tribal structure of the Plateau Indians was very similar to that of the Coastal Indians

There were, however some very important differences. The most respected members became leaders and chiefs. When there was war, the chief became a military leader. Larger tribes had more than one chief. Each chief would have different areas of responsibility and leadership. The Plateau Indians did not value materials and slaves as much as the Coastal Indians. The main concern of the Plateau Indians was survival. The Plateau Indians spoke many different languages. Some of them were Interior Salish, Sahaptin, Chinook, Molala, and Shoshonean. Because there were so many languages that were spoken, communication between tribes was very difficult. To communicate with each other, they used sign language and Chinook Jargon. This was a mixture of Chinook, English, and French. Today they speak English.