British Columbia is the westernmost province of Canada, bordered by the Pacific Ocean. With an area of it is Canada's third-largest province. The province is almost four times the size of the United Kingdom and larger than every United States state except Alaska. It is bounded on the northwest by the U.S. state of Alaska, directly north by Yukon and the Northwest Territories, on the east by Alberta, and on the south by the U.S. states of Washington, Idaho, and Montana. Formerly part of the British Empire, the southern border of British Columbia was established by the 1846 Oregon Treaty. The province is dominated by mountain ranges, among them the Canadian Rockies but dominantly the Coast Mountains, Cassiar Mountains, and the Columbia Mountains. Most of the population is concentrated on the Pacific coast, notably in the area of Vancouver, located on the southwestern tip of the mainland, which is known as the Lower Mainland. It is the most mountainous province of Canada. Statistics Total area: Land area: Water area: (2.1%) Physical geography British Columbia is customarily divided into three main regions, the Interior, the Coast and the Lower Mainland (though the last-named is technically part of the Coast). These are broken up by a loose and often overlapping system of cultural-geographic regions, often based on river basins but sometimes spanning them. Examples of the former would be the Kootenays, the Okanagan, and the Chilcotin, while of the latter would be the Lillooet Country and Cariboo. Important subareas of these include the Fraser Valley, part of the Lower Mainland, the Fraser Canyon (which overlaps with various regions) and the Robson Valley, which is the uppermost basin of the Fraser River southeast of Prince George. Vancouver Island is seen as its own region within the Coast, as are the Haida Gwaii (Queen Charlotte Islands) and the Gulf Islands. Terrain The Canadian Rockies, Coast Mountains and Inside Passage provide some of British Columbia's renowned and spectacular scenery. These landforms provide the backdrop and context for a growing outdoor adventure and ecotourism industry. In the southwestern corner of B.C., the Lower Fraser Valley forms a flat, fertile triangle of intensively used land. The city of Penticton and the small towns Oliver, and Osoyoos have some of the warmest summer climates in Canada, although the hottest spots are the towns of Lillooet and Lytton in the Fraser Canyon. Nearly all of the Coast including much