The British Columbia Interior, popularly referred to as the BC Interior or simply the Interior, is a geographic region of the Canadian province of British Columbia. While the exact boundaries are variously defined, the British Columbia Interior is generally defined to include the 14 regional districts that do not have coastline along the Pacific Ocean or Salish Sea, and are not part of the Lower Mainland. Other boundaries may exclude parts of or even entire regional districts, or expand the definition to include the regional districts of Fraser Valley, Squamish–Lillooet, and Kitimat–Stikine.
Home to just under 1 million people, the British Columbia Interior's 14 regional districts contain many cities, towns, airports, and associated regional, provincial, and national parks connected by the province's highway and railway network. The region is known for the complexity of its landforms, the result of millions of years of tectonic plate movements. The ecology of the region is dominated by temperate coniferous forest with patches of alpine tundra found atop its numerous mountain ranges.
The region, which includes the Interior Plateau as well as various mountain ranges and the valleys between them, comprises everything inland from the Coast Mountains and reaching east to the Rocky Mountains and, in the northeast, British Columbia's sector of the Prairies, the Peace River Block. "Interior" is usually and properly capitalized but turns up in lower-case in various books and magazines. The non-coastal areas of the province are considered to be "in the Interior", although the sparsely populated regions of its northern half are usually referred to only as "the North".
The town of Hope, at the eastern end of the Fraser Valley and at the foot of the Fraser Canyon, is often considered the "Gateway to the Interior" and bears an entrance arch to that effect, though in practical terms the Interior does not begin until somewhere between Yale and Boston Bar, in the Fraser Canyon, or until the summits of the Coquihalla and Allison Passes. The boundary between "the Coast" and "the Interior" along the Highway 99 corridor is nominally between Whistler and Pemberton, as Pemberton is often described as being in the Interior, but from the inland perspective it is often seen as part of the Coast because of its wetter climate and close ties to the Lower Mainland.
There are many subregions within the Interior, some regions in their own right, and although there are no precise definitions, it is often broken up informally as the Northern Interior, the Central Interior, the Southern Interior, the Northeast Interior and Southeast Interior, and these names often appear in non-governmental organizations and company names as well as in government administrative districts and ministerial regions, and in weather reports.
The Northern Interior begins somewhere between the Cariboo and the city of Prince George, which lies just south of the big bend in the upper Fraser. The city of Quesnel may be considered to be part of the Northern Interior, but it is usually conceived of as primarily being in the Cariboo, which is normally termed the Central Interior, or North-Central Interior. The Northern Interior includes Robson Valley (the upper reaches of the Fraser basin) to the southeast of Prince George as well as the Omineca District and the Bulkley and Nechako basins. The communities of the upper Skeena are sometimes referred to as being in the Northern Interior, though in cultural terms and usual usage they are part of the North Coast, which is associated in regional terms usually with the South and Central Coast and Vancouver Island.