THE word ``Arctic'' conjures images of snarling wolves and howling winds, of Jack London's heroes fumbling to build a fire in blinding, driving snow. Such images can be dangerously true in winter, but summer here, 200 miles above Alaska's Arctic Circle, makes for warmer memories - of standing alongside the Koyukuk River as the midnight sun hangs over distant mountains; of a moose swimming across the John River, its long muzzle only inches above the current; of sharp-beaked loons with diamond-speckled backs flapping wildly out of the water. This land never saw a professional explorer until 1929, when an energetic forester named Robert Marshall led a pack horse into the wilderness above the tiny towns of Bettles and Wiseman.
The park hasn't changed much since Marshall's days. A crowded weekend means it's possible to be the only human beings in this vast, primordial stretch of mountains, valleys, and tundra.
We began our two-week expedition on the Arctic Divide at one of the few lakes with a name.
Like most of the lakes in the central Brooks Range, Lonely Lake was scooped out by glaciers thousands of years ago. It is a small lake, maybe 100 yards wide, set in a broad, green valley with mountains rising gradually to the south and north, with no trees to block the view. To get here, we chartered a small float plane. Descending toward Lonely Lake, we were greeted by one of the local residents, a grizzly bear, rumbling across the tundra in search of a meal.
The grizzly paused to watch as the pilot banked the plane for a better look and a noisy suggestion to the bear that he continue on. We figured the bear was about half a mile away from where we wanted to stake our tents. Camping under the midnight sun
Our plan was to hike, over the next eight days, from Lonely Lake to the John River 30 miles away. There the pilot would meet us with two canoes for the second part of our trip. It was a 100-mile float down the John River to an abandoned mining town at the confluence with the Koyukuk.
From the confluence, we would pull our boats five miles up the Koyukuk to Bettles (pop., 80), a town built around an airstrip that serves as the jumping-off point into this park. All this takes place miles from the nearest help. In fact, during the 14 days of our expedition, we saw no one else.
Although it was near midnight when we said goodbye to our pilot, the sun hung above us as if it were midday. In the clean air, the light is bright. For half the year, the sun never dips more than briefly below the horizon. Such sunsets lack the photochemical spectacle of, say, polluted Los Angeles, but they are marvelous in their clarity.
The sun was our only source of heat on the treeless tundra. We learned quickly to respond to it, because when it hid behind clouds, we instantly became cold.
We spent the first two days checking equipment, climbing a nearby peak, and fishing in the lake below our campsite. Evenings, we explored the immediate area around camp.
We spotted a black-and-gray wolf eyeing us across the tundra. But the moment we stepped toward it, the wolf broke away and disappeared from view in seconds. The wolf, however, led us to our first rack of caribou antlers. They were ghostly white, rising eerily from the green tundra.
At the lake, fish were rising to snap at the mosquitoes floating on the surface. We had heard stories of virgin Arctic lakes that have never been fished. They may be true: In less than five minutes, we caught four Arctic grayling, a succulent white fish similar to trout, with nothing more than a simple spin rod and red lure. Somewhere on the tundra
From a distance, tundra is easily the most deceptive form of topography in the wilderness. Vast stretches of green roll up the sides of hills like Wisconsin pastureland. But don't be fooled; the proof is in the walking. Up close, tundra is a giant mat of tangled vegetation designed to ensnare feet.
It's a soggy desert of sedge and cotton grasses, reindeer moss, Labrador tea, and sphagnum. At the center of this walking nightmare is the tussock, a giant mushroom-shaped clump of tightly woven grass that thrives in marshy, poorly drained land.
Like most of Alaska, the Gates of the Arctic is covered by permafrost, a layer of permanently frozen ground that usually begins an arm's length beneath the topsoil. The permafrost limits the amount of water the ground can absorb. The resulting marshes breed tussocks by the billions.
At their worst, tussocks can grow two feet high in closely gathered bunches that cover entire valleys. You can't walk on top of them because their narrow stems buckle, sending you reeling into the muck. The alternative is to step around them, swinging legs over the top and carefully choosing a safe landing spot. Even then, feet become soaked in the ankle-deep moss and water. With 75-pound packs, we managed little more than a mile an hour.
Avoiding tussocks is the chief preoccupation of the Brooks Range backpacker, but the options are limited. After crossing a mile-long valley infested by tussocks, we headed toward the mouth of Agiak Creek and a rocky gravel bar that felt like a city sidewalk by comparison.
Eventually, the river widened and the easy gravel bars disappeared. This led to another form of hiker's frustration: Picking your way through the dense thickets of willow, alder, and cottonwood that press in on the river.
Trudging through tussocks and alder is made more maddening by the mosquitoes that hover in clouds around you. These pesky insects are absolutely everywhere. They descend on hikers in swarms. It is not unusual to hit a dozen at a slap.
It is impossible to avoid getting bitten. To fight back, we carried the latest, strongest repellent on the market - DEET. The alternative to DEET is a head net. It's effective, but the meshing obscures the views of the mountains and valleys and renders all colors a neutral gray. Sometimes, with feet wet and heads in clouds of mosquitoes, we wondered why we were there at all. Atop a nameless mountain
Climbing mountains in the Brooks Range, even peaks with jagged edges and precipitous falls, is easier than scaling Wyoming's Tetons or Washington's Cascades. There are no tussocks, no mosquitoes here. Only wind, blue sky, and emerald lakes. This is the payoff for hours of brutal hiking.
These mountains offer a variety of gentle ridges that require no ropes or pitons. You walk to the top, scrambling over boulders or across dry alpine tundra that feels like carpet under your feet.
Or you can try overcoming more ominous peaks of schist and shale that have thrust through the earth's crust at crazy angles. There are no glaciers or snowfields to cross. Climbers can leave crampons at home and use an ice ax as a walking stick.
Yet, despite the relative ease of climbing a mountain, the view from the top is spectacular. The summit is a razor-sharp ridge that falls away sharply on one side to the lake and, on the other, to a rugged valley. The wind forced us down prematurely, but we stopped at the lake to dine on peanut butter, pita bread, and gorp - the traditional hiking snack of nuts, raisins, dates, and dried fruit.
In moments like these, when the sun warmed us, there was no better place to be.