Kelowna is located midway along the shores of Okanagan Lake in the Okanagan Valley. The Okanagan Valley is part of British Columbia’s Interior Plateau and is characterized by a string of lakes created by glaciation. This glacial activity occurred during the Tertiary and Quaternary periods when mile-thick ice layers retreated 10,000 years ago, scraping the surface and leaving behind valuable sedimentary deposits along its borders. Additional mountain river erosion and flooding left behind nutrient and mineral-rich soils which today still form the foundation of the Okanagan’s successful agricultural economy.
Okanagan Lake, the largest of the lakes, is 135 km (84 miles) long and ranges from about 3.2 to 6.4 km wide. East of Okanagan Lake are Swan, Kalamalka (a Salish word meaning lake of many colours) and Wood lakes. To the south are Skaha, Vaseux and Osoyoos lakes. The system drains south into the Okanagan River, crosses the border into Washington, and joins the Columbia River. The Columbia then veers west and carves a path through the Cascade and Coast Mountain ranges to drain into the Pacific Ocean.
Three mountain ranges surround the region: the Columbia Mountains, a range of the Rockies, and comprised of the Purcell, Selkirk, Monashee and Cariboo sub-ranges lay to the east of the Okanagan Valley; the Cascade Mountains, specifically the Okanagan, Hozameen and Skagit ranges, form the south-western border; and the Coastal Mountains are to the west.