The Biltmore House, in Asheville, North Carolina was once home to a branch of the super-wealthy Vanderbilt family. Now, it attracts a million people a year to the sprawling estate in the Blue Ridge Mountains. There’s a long history of opulence and intrigue there. But it is also where the original idea of sustainable forestry was born in America. All that and more is explored in a new book by New York Times best-selling author Denise Kiernan. “The Last Castle” hit shelves in late September, and