This untamed landscape of rugged, peaks, deep valleys and icy lakes and rivers, is known as the ‘Last Great Wilderness. Human activity has hardly touched the central and eastern parts of Brooks Range – the tip of the Rocky Mountains that spreads across northern Alaska for 600 miles (1000km). Grizzly bears, wolverines inhabitants, along with horned Dall sheep, arctic foxes and caribous.
The Brooks Range forms a great will across this northern tip of the United States. On its south side grow forests of spindly trees, whose trunks can take 300 years to grow 3in(75mm) wider.
To the north of the mountain wall lies the Alaskan North Slope, a vast wasteland of frozen ground. During the few months of warmth and daylight, it bursts into life, with flowers blooming among lichens, sedges, mosses and stunted willows.
Few people live in this barren land. In midwinter, it is dark all day and the temperature, which routinely falls to a numbing -30C (-22F), can fall as low as -45C (-49F). Settlements can be very isolated. Arctic Village, on the south side of Brooks Range, is accessible only by air, and by snow-mobiles or dog-sleigh teams.
The problem in this area hunt porcupine caribous. These arctic deer spend the winter south of Brooks Range, in valleys leading to the Porcupine River that gives them their name. Each spring the 160,000-strong herd leaves its winter grounds and migrates across the Brooks Range to the coastal plains.
There, the calves are born and the caribous graze on Lichens and grasses that fatten them ready for the bitterly cold winter. The area has been dubbed ‘America’s Serengeti’, for the caribou’s migration recalls the great migration of wildebeests, zebras and gazelles that takes place in east Africa’s Serengeti National Park.
The area was described as ‘ Gates of the Arctic’ by Bob Marshall, a forester and explorer. He has a fascination for places visited by no one else and, in the 1930s, explored the valleys of Brooks range and scaled many of its mountains. ‘There is something glorious,’ he said, in travelling beyond the ends of the Earth, in living in a different world which men have not discovered and hardy visitors have discovered the unique wilderness areas of Brooks Range.