Recent Listings in the National & State Registers.Colorado State Register of Historic Properties.Preservation Planning Unit Resource Center.Information for Archaeologists, Paleontologists and Researchers.Information for Students and Volunteers.Information for Museums and Curatorial Repositories.State-Approved Museums and Curatorial Repositories Expand.Office of Archaeology & Historic Preservation.Secretary of the Interior's Standards for Rehabilitation.Federal Historic Tax Credit Impact in Colorado.Archaeology & Historic Preservation Month.Program for Avocational Archaeological Certification (PAAC) Expand.About the State Historic Preservation Office Expand.