A production of The Documentary Guild in association with WGBH Boston for Nova ; WGBH Educational Foundation ; Executive editor, William Grant ; executive producer, Paula S. Apsell ; written, produced and directed by Rob Whittlesey and Noel Buckner
[presented by] U.S. Geological Survey in collaboration with the National Park Service ; producer-director, Anne Tubiolo ; writers, Sandra Clark, Anne Tubiolo, Elizabeth Romanaux