Book excerpt: The Delaware River flows out of New York's Catskill Mountains and winds its way through woodland and rural farmland, through the great Water Gap ravine, and finally past one of the world's most industrialized riverfronts. Yet it remains one of the country's last undammed rivers, with a natural life as rich and varied as its human history. In Natural Lives, Modern Times, Bruce Stutz has written a thoroughly modern natural history, blending keen observations of the nature of the Delaware's enduring complex of river, glacial streams, marshlands, and forest with glimpses of history and folklore and with luminous portraits of those whose lives are sustained by the river. The Delaware was the waterway of the nation's first mercantile, philosophical, scientific, cultural, and industrial heartland, hosting immigrants from Europe, Africa, and the Mediterranean, all looking for new lives along the ancient river. In this always entertaining and often haunting intertwining of human and natural history, Bruce Stutz discovers those who regret what has been lost and those passionate about preserving what remains. Most of all, however, he lets us see what's at stake in a wonderfully diverse world. Not since Mark Twain has anyone taken such a freewheeling river journey.