Remote and wild, the Yukon is a river of haunting beauty and dangerous extremes — a place where the "call of the wild" is still strong. In summer, it is a relentless giant, carving its way 2,000 miles across Canada and Alaska. In winter, -50C temperatures transform it into a river of ice. Home to grizzlies, moose and great runs of salmon, the Yukon lies at the heart of a vast northern wilderness. Bears delay their winter hibernation to fish for a final salmon feast, while the frozen river provides a lifeline for lynx and a race track for intrepid dog sledders. From indigenous hunters to gold-prospectors, musk ox to caribou, the Yukon's natural riches have long sustained people and animals and continue to do so despite its changing fortunes.