High Quality Content by WIKIPEDIA articles! The Okanagan Highland is a plateau-like hilly area in British Columbia, Canada, and the U.S. state of Washington (where it is spelled Okanogan Highland). It lies between the Okanagan Valley on its west and the Kettle River on its east, and geologically is more or less an extension of the Thompson Plateau, which lies west of the Okanagan. Its northern perimeter is the valley of the Shuswap River, while its southern limit is the FDR Reservoir (the impounded Columbia River above Grand Coulee Dam) in Washington State. Some definitions may place the northern limit at the Coldstream Valley, east of Vernon, British Columbia, as that is the southern limit of the Shuswap Highland.