Interior Salish peoples

Interior Salish peoples are Indigenous peoples of the Northwest Plateau, who are centered in south British Columbia in Canada and northwestern Washington, northern Idaho, and western Montana in the United States. They speak Interior Salish languages, a branch of the Salishan language phylum. Salish language–speaking peoples to the West are the Coast Salish peoples. To the south are Sahaptian language–speaking tribes, especially the Nez Perce.
Historically, Interior Salish peoples had seasonal settlements to fish, hunt, and gather abundant wild plants. In the winter, they lived in round, semi-subterranean pit houses with thatched roofs. In summer, they built conical homes from tule reed mats. Villages were politically autonomous.
Interior Salish peoples did not encounter Europeans until 1793, when Scottish-Canadian explorer Alexander Mackenzie entered Secwepemc territory. Canadian explorer and fur trader Simon Fraser met several Interior Salish peoples when traveling down the Fraser River in 1808. After contact, Interior Salish peoples adopted some cultural traits from Indigenous peoples of the Great Basin and Northern Plains to their south and west, but not linguistic traits.
In the 1870s, Canada established several Indian reserves for Interior Salish peoples that were a fraction of their historical homelands in British Columbia. The Interior Salish First Nations have fought to reclaim their lands ever since.

Northern

There are three Northern Interior Salish languages: Shuswap, Lillooet, and Thompson. Indigenous peoples speaking Northern Interior Salishan languages are located in southwestern BC:

There are four languages belonging to the Southern branch of Interior Salish: Okanagan, Columbian, Kalispel, and Cour d'Alene.
Peoples speaking the Okanagan language :

Sinixt, also known as the Arrow Lakes Band or the Lakes Band, southwestern BC and northeastern WA
Colville, northeastern WA and southwestern BC
Syilx, also known as the Okanagan, southwestern BC, northeastern WA
*Northern Okanagan
*Southern Okanagan
Methow, eastern WA
Nespelem, eastern WA
Sanpoil, eastern WA

Peoples speaking the Columbian language are all located in northeastern WA:

Peoples speaking the Kalispel language :

Spokane, northeastern WA
* [Lower Spokane people|Spokane people|Lower Spokane]
* Middle Spokane
* Upper Spokane
Pend d'Oreille, also known as the Kalispel, northeastern WA, northern ID, western MT
* Kalispel, also known as the Lower Pend d'Oreille or Lower Kalispel, on the Pend Oreille and Clark Fork rivers to the confluence with the Flathead River, northeastern WA, northern ID, and northwestern MT
** Lower Kalispel, on the Pend Oreille River to Lake Pend Oreille, northeastern WA and northern ID
** Upper Kalispel, on the Clark Fork River to the confluence with the Flathead River, northern ID and northwestern MT,
* Pend d'Oreille, also known as the Upper Pend d'Oreille or Upper Kalispel, around Flathead Lake, the Flathead and Clark Fork rivers above the confluence, and the Bitterroot Valley, western MT
Bitterroot Salish, also called the Flathead or the Salish, Bitterroot Valley and across the Continental Divide along the Missouri and Yellowstone rivers to Billings, southern MT

Just one people speaks the Cour d'Alene language:

Coeur d'Alene people, also known as the Schitsu'umsh or Skitswish, eastern WA and northern ID
*Spokane River-Coeur d'Alene Lake division
*Coeur d'Alene River division
*Saint Joe River division