essentially every major river from the Yukon River in the north to the mouth of the Colorado River in the south, and east to the headwaters of the Missouri River tributaries. American fur trade competition was effectively blocked through various strategies, including selectively overhunting frontier regions to create "fur deserts", and the construction of forts on the Pacific Northwest coast to intercept furs before American ships could acquire them. The HBC also diversified their economic activity and began exporting agricultural foodstuffs, salmon, lumber, and other products. Russian Alaska, Hawaii, and Mexican California were developed as markets for these exports. The HBC opened agencies in Sitka, Honolulu, and Yerba Buena (San Francisco) to facilitate the trade. Fort Vancouver was the nexus for the fur trade on the Pacific Coast; its influence reached from the Rocky Mountains to the Hawaiian Islands, and from Alaska into Mexican-controlled California. At its pinnacle, Fort Vancouver watched over 34 outposts, 24 ports, six ships, and 600 employees. The employment of Hawaiian Kanakas was gradually expanded until at least 207 in the Columbia Department by 1845, with 119 located at Fort Vancouver. Also, for many settlers the fort became the last stop on the Oregon Trail as they could get supplies before starting their homestead. By 1843 the Hudson's Bay Company operated numerous posts in the Columbia Department, including Fort Vancouver, Fort George (Astoria), Fort Nisqually, Fort Umpqua, Fort Langley, Fort Colville, Fort Okanogan, Fort Kamloops, Fort Alexandria, Flathead Post, Kootanae House, Fort Boise, Fort Hall, Fort Simpson, Fort Taku, Fort McLoughlin (in Milbanke Sound), Fort Stikine, as well as a number of others. Increasing numbers of American settlers arriving on the Oregon Trail gave rise to the Oregon boundary dispute. With the signing of the Oregon Treaty in 1846 the U.S.-British boundary was fixed on the 49th parallel. This effectively destroyed the geographical logic of the HBC's Columbia Department, since the lower Columbia River was the core and lifeline of the system. The U.S. soon organized its portion as the Oregon Territory. The administrative headquarters of fur operations, and of the Columbia Department, then shifted to Fort Victoria, which had been founded by James Douglas in 1843 as a fall back position in preparation for the "worst case" scenario settlement of the dispute, in the face of manifest destiny. By 1846, the Columbia District proper had been more than halved and the name had fallen into