The U.S. Forest Service plans to close a century-old Portland-based forest research station and a regional U.S. Forest Service headquarters but open a new federal office in Salem in a massive restructuring of the federal agency. The movements are part of a broad plan Forest Service officials announced Tuesday to move the agency operations westward, including shifting headquarters in Washington, D.C., to Salt Lake City. Officials will also close all nine regional Forest Service offices across the country, including the Northwest office in Portland, and consolidate seven state-based research stations, including the 100-year-old Pacific Northwest Research Station, also in Portland, into a single research station in Fort Collins, Colorado. Smaller Forest Service research and development facilities in Corvallis and La Grande that are associated with the Pacific Northwest Research Station will remain open.