Every year millions of Americans visit national parks and monuments, state and municipal parks, battlefields, historic houses, and museums. By means of guided walks and talks, tours, exhibits, and signs, visitors experience these areas through a very special kind of communication technique known as ''interpretation.'' For fifty years, Freeman Tilden's Interpreting Our Heritage has been an indispensable sourcebook for those who are responsible for developing and delivering interpretive programs. This expanded and revised anniversary edition includes not only Tilden's classic work but also an entirely new selection of accompanying photographs as well as five additional essays by Tilden on the art and craft of interpretation. Whether the challenge is to make a prehistoric site come to life; to explain the geological basis behind a particular rock formation; to touch the hearts and minds of visitors to battlefields, historic homes, and sites; or to teach a child about the wonders of the natural world, Tilden's book, with its explanation of the famed ''six principles'' of interpretation, provides a guiding hand.