Copyright, yet again

Here is a chart, explicitly explaining when items enter the public domain.

Which is to say, everything that I am interested in working with will be available sometime after I am dead.

The work that I would really like to do, work with the collected folktales of the Ozarks, I really can't, unless I track down a copyright holder. Because the people who were telling the stories are, of course, dead, so I can't track them down and ask them to tell me. And besides, the stories are copyrighted by someone else. Frustrating, frustrating.