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. In the Treaty of 1818 between the U.S. and Britain, the two powers agreed that each had free and open access to the Oregon Country. This "joint occupation" continued until the Oregon Treaty of 1846, yet American attempts to conduct commercial operations in the region failed in the face of competition by the Hudson's Bay Company. The only sphere in which the Americans temporarily dominated was the maritime fur trade along the coast. But the HBC successfully took over the coastal maritime trade during the 1830s by for example constructing trading forts. The North West Company found the Native Americans of the Columbia region generally unwilling to work as fur trappers and hunters. The company depended upon native labor east of the Rocky Mountains and found it difficult to operate without assistance in the west. For this reason the company began, in 1815, to bring groups of Iroquois, skilled at hunting and trapping, from the Montreal region to the Pacific Northwest. This practice soon became standard policy and was continued for many years by both the North West Company and the Hudson's Bay Company and was essential for the extension of the fur trade into much of the Columbia basin. The Iroquois were intended not only to support company personnel but, it was hoped, teach local natives the skills of hunting and trapping, and convince them to take up the work. This effort was largely unsuccessful. The reason generally given for the unwillingness of the natives to take up trapping and hunting was that their way of life was highly focused on salmon and fishing, and that the abundance of salmon resulted in little incentive for taking up hunting and trapping. Instead of cooperation there were altercations between the Iroquois and local natives. In 1816 parties of the North West Company, including a number of Iroquois, explored the Cowlitz River valley and the Willamette Valley, reaching as far south as the Umpqua River. Both exploring expeditions ended with violent clashes between the Iroquois and local natives. In addition the North West Company began to hire Native Hawaiians, known as Kanakas. This practice was