The ecology of the region is dominated by temperate coniferous forest with patches of alpine tundra found atop its numerous mountain ranges.

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 term is used to mean the whole of the Northeastern Interior east of the Rockies, including Fort Nelson and other parts of the Liard drainage, and before W.A.C.

The Central Interior is composed, roughly, of the Chilcotin, Cariboo, Bridge River-Lillooet, Fraser Canyon, Nicola, Thompson and Kamloops-Shuswap Countries.

The Southern Interior roughly falls south of the Thompson River and Shuswap Country (corresponding mostly to the post-Oregon Treaty remainder of the old, original, Hudson's Bay Company Columbia District).

All often correspond to linguistic and cultural-political divisions of the First Nations as aboriginal history was also shaped by the landscape's isolating and defining characteristics as settler culture.

[2] The British Columbia Interior's society and culture is affected by the populations of First Nations Canadians and French-Canadians people and residents living close to the US - Canada border.

The TCH enters the region from the south after 186 km (116 mi) through the Fraser Canyon in the Lower Mainland toward Cache Creek.

As a mostly high mobility highway with only occasional mandatory stops, it heads east for 79 km (49 mi) through to Kamloops where it becomes a short freeway.