The London-based Hudson's Bay Company established an extensive fur trading network throughout the Pacific Northwest, using two dozen posts, six ships, and about 600 employees during peak seasons. Fort Vancouver served as the administrative center and principal supply depot of this Columbia Department, controlling 700,000 square miles from Russian Alaska to Mexican California and from the Rocky Mountains to the Pacific Ocean. The fort became a center of activity and influence, supported by a multicultural village with inhabitants from more than 35 different ethnic and tribal groups. The region's first hospital, school, library, grist mill, saw mill, dairy, shipbuilding, and orchard were all centered there. Since 1948, it has been part of the National Park System and today is also part of the Vancouver National Historic Reserve. Fort Vancouver is designated the premier historical archaeological site in the Pacific Northwest, where archaeological and historical research guide its reconstruction and the sharing of its past. More than two million museum items are cared for there, spanning the American Indian, fur trade, and U.S. Army occupations of the area.