Sarah Palin, say what you will: this polar bear was definitely endangered. For days it had scarcely moved, but had lain, muddy brown and injured, on the shores of the Arctic Ocean amid the rigs, pipes and processing plants of Alaska's Prudhoe Bay oil fields.
It had lost a fight. The winning bear had retreated, but was being tracked by security teams who reported that the victor was circling round and returning to slay its rival. The oil workers, who during their weeks-long shifts saw little in the way of life-and-death entertainment, were riveted.
"Nobody's to leave the bus," our security attachment told us as we made our way past the checkpoint that separates the Prudhoe Bay oilfields – land leased by the oil companies that is not accessible to the public except on organised tours – from Deadhorse, the gruesomely named conglomeration of camps where the oil company workers sleep and eat. "The polar bear's too dangerous."
As we peered through binoculars from our bus at this distant, defeated creature, I considered that it was unlikely to be capable of the flat-out sprint it would require to gobble up faraway tourists, even those of the well-fed, white-sneaker kind. Then, as if sensing it was being judged, the polar bear rose painfully on to its haunches, turned towards us, and stared.
I'd flown that morning from Fairbanks to Deadhorse to join a tour group driving from the shores of the ocean down the Dalton Highway, the road that follows the Alaska pipeline for almost 400 miles (666km to be precise and environmentalists must have something to say about that number) from Prudhoe Bay to Livengood, a little over 120 miles (200km) north of Fairbanks.
Built by the oil firms in 1974 – construction took just five months – the Dalton Highway passes through some of the most pristine wilderness on our planet, a world that's inhabited by musk oxen, caribou, wolves, moose, bears and very few people. The road is narrow and rough; three-quarters of it is unpaved. Created as a "haul road" to move oil field machinery on tractor-trailer rigs, it was not fully opened to the public until 1994.
We stayed that first night in Deadhorse. It is a town with a permanent population of one: a cat named Deadhorse Denver who's lived in the general store for the past six years. Everyone else in Deadhorse works shifts. Our accommodation was of the portable cabin kind, with no running water but a blastingly efficient heater that would blow the icicles out of the bitterest of winter days. But despite the boxy, functional buildings and the piles of metal paraphernalia about the camp, this was a strikingly beautiful place. The land was flat and green, the grass scattered with the white fluff of Arctic cotton grass and spotted with clear lakes named after women: there was a Colleen, then an Olivia.
"The guys that worked up here in the early days named the lakes for their wives and girlfriends," Rob Jordan, our guide, explained. "But the workforce here is transient, and nobody knows any more who Colleen or Olivia were."
These patches of water are popular with the birds: a crowd of red-necked phalaropes on one, and two tundra swans with three cygnets on another.
Our luck with wildlife viewing continued the next morning as our road trip began. Just three miles out of Deadhorse, we came upon perhaps 30 or 40 musk oxen grazing by the roadside. Once extinct in Alaska, these shaggy creatures with their stooping posture and little white horns, like curly Alice bands, were reintroduced from Greenland in the 1930s. The Inupiaq people call them "omingmak", meaning "animal with skin like a beard".
Musk oxen appear to tolerate the road and the pipeline, though wildlife and oil are controversial partners. The majority of Alaskans are in favour of oil development. The economy of this state, which marked 50 years of statehood in January, depends on it: 90 per cent of Alaska's general fund income is from oil and gas revenue. Each year, the state invests a proportion of its income from minerals into a vehicle called the Permanent Fund, from which every resident of Alaska receives an annual dividend payment. In 2008, each man, woman and child received more than $3,000 (£2,000).
It doesn't take a genius to work out why further exploration for oil is popular. Arctic Power, a group that lobbies the US government to approve the much-debated oil exploration off the coastal plain of the Arctic National Wildlife Refuge (ANWR), a protected wilderness which lies to the east of Prudhoe Bay, claims that almost 80 per cent of Alaskans are in favour; much of the argument rests on the apparent environmental success of the pipeline I was following now. It was constructed with 579 animal crossings. Wildlife has right of way on the Dalton Highway: if a large herd of caribou chooses to cross in front of your vehicle, you'll just have to wait a couple of hours. The pro-oil lobby cites the fact that the central Arctic caribou herd, whose territory we were passing through, has substantially increased in numbers since the 1970s (for many reasons, the porcupine caribou herd – which is threatened by ANWR oil exploration – would be unlikely to prosper in the same way) though Republican Congresswoman Michele Bachmann became a little carried away, perhaps, when she claimed in a recent interview that the animals love the warmth created by the pipeline, which has "become a meeting ground and coffee klatch for the caribou".
We saw just one caribou (sans espresso), then another herd of musk oxen. A lone red fox with a charcoal-streaked face trotted across the tundra. The pipeline ran alongside us – permafrost dictates that more than half of the pipeline is raised above ground – weaving across the land like a massive silver snake. The oil inside it would be moving at around walking pace; it would take about 12 days to travel the 780 miles from Prudhoe Bay to the shipping terminus at Valdez.
Driving high into the hills of the Brooks Range we looked down on slithers of rivers that braided in shiny platinum beneath us across a vast plateau. We dropped back down. Along the roadside, fireweed blazed magenta-pink. Then we arrived at Coldfoot Camp, to spend the night.
Back in the gold-rush days, Coldfoot was a mining community. The story goes that the camp was named after a group of hopeful stampeders who arrived in the summer of 1900, got cold feet at the prospect of the winter ahead and turned on their heels and fled south. In those days, Coldfoot had two roadhouses, two stores, a gambling hall and seven saloons.
What was left of the mining community moved four miles north to Wiseman in 1908. Coldfoot was re-established in 1970 as a camp for construction workers on the Dalton Highway. Now it's little more than a truckers' stop with a café, bar, rudimentary motel, and petrol pump.
"Eat here and get gas," chirp the notices on each table. We ordered burgers and fries. In a separate room, marked "Truck Drivers Only", a long table was surrounded by men dressed in dungarees and baseball caps, who smoked and let rip raucous laughter.
We took a detour to Wiseman the next morning, a short distance off the highway. Here, we were given a tour by one of the village's 13 inhabitants, Jack Reakoff. We visited the tiny chapel where the residents hold a service each Sunday morning, and the gloriously dilapidated cabins that had been occupied decades ago and never pulled down. It seemed a serenely peaceful place, frequented by people living truly in tune with their environment: in this remote outpost, they must understand the land if they're to survive.
"My father was a trapper. He started to teach me about the land when I was 18 months old," Reakoff told us as we stood in his cluttered log-cabin kitchen whose walls were packed with family photographs. Now Reakoff, too, lives a largely subsistence lifestyle hunting moose, Dall's sheep, and caribou for food. Even here, above the Arctic Circle, where temperatures never rise above freezing from October to April, he grows more than 90 per cent of the vegetables he eats: potatoes, beetroot, carrots and cabbage. He also traps wolves and martens for their pelts. On the side of one of his cabins are nailed rows of wolf skulls, while a pile of moose antlers make up a towering tree in his garden.
"I'm concerned about the wildlife in Alaska and the ever-increasing pressures exerted by humans," said Reakoff. Here was one Alaskan who was opposed to the development of oil exploration in ANWR. "Conservation units have proven to be the only way to protect natural wildlife populations – and there is no need to lease ANWR," he insisted, pointing out that the oil companies already have considerable other land on the North Slope open to them.
And if the oil lobby were to win? Reakoff believes the caribou would be displaced and their populations eroded. "These are the last of the large herds in Alaska," he said. "There are no more."
Read this: Polly Evans is the author of Mad Dogs and an Englishwoman, Bantam, £7.99
How to get there
Polly Evans was the guest of the Northern Alaska Tour Company (00 1 907 474 8600; northern alaska.com), which offers an Arctic Ocean Adventure from $989, based on two sharing, between 22 May and 8 September. That includes one flight between Fairbanks and Prudhoe Bay, transport and accommodation. Shorter road trips and flight-seeing tours are also available. Return international flights from London to Seattle with British Airways (0844 493 0787; ba.com) cost from £420. Onward connections to Fairbanks with Alaska Airlines (01992 441517; alaska airlines.co.uk) cost from $715 return.
Alaska Travel Industry Association (01483 500006; travel-alaska .co.uk).