Ed was one of the featured book authors at a festival in Bozeman, MT. He lived there for a number of years. From the Bozeman Daily Chronicle, August 24th, 2008:
ALTON STRUPP/CHRONICLE Author Edward Hemingway, the grandson of Ernest Hemingway, signs books and talks with visitors at the Bozeman Public Library's Children's Festival of the Book on Saturday afternoon
The full context is here.