For fifty years, Interpreting Our Heritage has been an indispensable sourcebook for those who are responsible for and who respond to interpretive materials at national parks and monuments. This anniversary edition includes an entirely new selection of photographs, six additional essays by Freeman Tilden, and a new foreword and introduction that put this classic work into perspective for present and future generations. Whether the problem is to make a prehistoric site come to life or to explain the geological theory behind a particular rock formation, Tilden provides helpful principles to follow.