Which tribes spoke Salishan languages in the Plateau region?

In the Plateau region, the tribes that speak Salishan languages are categorized into Northern Plateau and Interior Salish groups. It is important to note that while some early historical works incorrectly labeled all Salishan-speaking groups as "Flathead," this is inaccurate; the term refers to a specific tribe rather than the entire linguistic family.1

The tribes are divided as follows:

• Northern Plateau Salish: Includes the Shuswap, Lillooet, and Ntlakapamux (Thompson) tribes.1
• Interior Salish: Primarily located in the Upper Columbia area, this group includes the Okanagan, Sinkaietk, Lake, Wenatchee, Sanpoil, Nespelim, Spokan, Kalispel, Pend d’Oreille, Coeur d’Alene, and Flathead peoples.1

These languages are part of a broader family of approximately 23 North American Indian languages historically spoken across the Pacific Northwest and parts of Idaho, Montana, and southern British Columbia.2