The British Colombia Interior or BC Interior or Interior of British Columbia, is one of the three main regions of the Canadian province of British Columbia, another being the Lower Mainland.

The Lower Mainland is a name commonly applied to the region surrounding Vancouver. While the term Lower Mainland has been recorded from the earliest period of non-native settlement in British Columbia, it has never been officially defined in legal terms. However, the term has historically been in popular usage for over a century to describe a region that extends from Horseshoe Bay south to the Canada-United States border and east to Hope at the eastern end of the fraser Valley. Adjoining settles areas are included, but are not in the usual historical definition. Those boundaries do not coincide with various government administrative districts referencing Lower Mainland.

Similkameen Country incorporates the region of the Similkameen Valley between Osoyoos on the Canada/United States border in the east and the gold rush heritage town of Princeton in the west. For travelers heading east from Vancouver and the Fraser Valley, Similkameen Country is the gateway to the Okanagan Valley, The Kootenays and the BC Rockies. The landscape of the Similkameen is dominated by the Similkameen River and the rugged mountains of Cathedral Park in the south, a diverse topography varying from arid valleys to soaring snow-capped mountain peeks.

Cattle ranching and horse breeding are strong industries in the valley, and the fabulously sunny climate makes the Lower Similkameen Valley one of the finest fruit, vegetable and wine growing areas in North America.