[6] The name Okanogan (Okanagan) also refers to a part of southern British Columbia.

Before Europeans arrived, the Okanogan County region was home to numerous indigenous peoples that would eventually become part of three Indian reservations referred to as the Northern Okanogans or Sinkaietk, Tokoratums, Kartars and Konkonelps.

They spoke in seven types of Interior Salish languages related to the Puget Sound tribes.

The camps consisted of teepee-like longhouses built with hides and bark.

A popular destination for this was the Kettle Falls, where the Columbia River dropped some 20 feet (6.1 m).

Due to its remoteness, the Okanogan County area was one of the last in Washington settled by Europeans.

It was an early thoroughfare used by prospectors to gain access to other communities, such as British Columbia.

Electric producer Grand Coulee Dam was constructed between 1933 and 1942, originally with two power plants, around the Okanogan and Grant counties at the former's southern border.

[7] In July 2014, the Carlton Complex wildfire burned over 250,000 acres (390 sq mi; 1,000 km2) in Okanogan County.

14.0% were of German, 9.5% English, 9.2% United States or American and 6.8% Irish ancestry.

24.50% of all households were made up of individuals, and 9.70% had someone living alone who was 65 years of age or older.

In fact, it became the longest-running national bellwether after Crook County, Oregon, voted for George H. W. Bush in 1992.