Okanogan County is located in North Central Washington, bordered on the north by British Columbia, Canada, the Columbia River to the south, the Cascade Mountains to the west, and Ferry County to the east. The County covers 5,281 square miles, making it the largest county in Washington. Only 30% of the land within the county is in private ownership due to the amount of state and federal land. The Colville Indian Reservation, located in the southeast corner of the county, occupies approximately 700.000 acres of Okanogan County and is an integral part of the heritage of the county. Taken from