The Shuswap Highland and Thompson Plateau, coming out of the unincorporated community of Grindrod, defines the northern border of the region; the terrain here is mountainous and hilly. The southern border is defined by Chelan, Douglas and Grant counties, although portions of these counties lie within the Okanagan Country. The Canada-United States border, which features an official crossing into Osoyoos from Oroville, separates the Okanagan and Okanogan subregions from each other. The Okanagan Highland and Okanagan Basin define the main geographic features, serving as plateau-like hilly areas. The Okanagan River and Okanagan Lake are the most prominent water features in the Okanagan Country, with a combined area of . According to Statistics Canada and the United States Census Bureau, the divided region comprises a total area of more than , larger than Belgium and Taiwan. The extended region within Chelan, Douglas and Grant divisions make a larger area. The largest municipality by area in the Okanagan Country is Spallumcheen, covering , making it larger than Seattle by land area. The southernmost community is Electric City, in Grant County. Other geographic features include Alta Lake, Columbia River, Cascade Mountains, Kalamalka Lake, North Gardner Mountain, Mahoney Lake, Mara Lake, McIntyre Bluff, Omak Lake, Osoyoos Lake, Similkameen River, Shuswap River, Skaha Lake, Swan Lake, Tuc-el-nuit Lake, Vaseaux Lake and Wood Lake.