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 continued and greatly expanded by the Hudson's Bay Company.