Under the North West Company the Columbia District was bounded, roughly, by the southern edge of the Thompson River on the north, and by the southern and eastern limits of the Columbia River basin. North and west of the Thompson was the New Caledonia fur district, in what is now north-central British Columbia. The Thompson River region was its own fur district, centered on a fur trading post that later became the city of Kamloops. The Thompson River District was the link between the Columbia and New Caledonia Districts.