It seemed strange to be boarding the chairlift in the dark.

Where there had been hundreds of people in the lift line only two hours earlier, there now were none. Where the sun had shone brightly over the valley's weather inversion, the moon now rose steadily.

The chairlift scooped us up and immediately we were being whisked up Big Mountain, through a layer of fog toward the summit, where dinner waited and dozens of other skiers anticipated using the moon's brilliance as a guide back down the slopes. Halfway up the mountain, the promise of moonlight peeked through the fog. After being transported through the fog layer, we were instantly thrust into another world. Ptarmigan Bowl, which looks like an ice cream scoop took out half of the upper mountain, glittered underneath the moonlight, and snowghosts cast long shadows across the hillside.

For almost 15 years, Big Mountain has invited skiers and snowboarders to partake in dinner at the Summit House, then be guided down the moonlit slopes.

Monday night's Moonlight Dine and Ski was the first of the season, featuring a sellout crowd. About 75 people took part in the dinner Monday, though only about half of those people skied back down; the rest took in the experience from a covered gondola and rode the chairlift to the base. Skiers and snowboarders were guided by members of the Big Mountain ski school, who provided a brief safety session before shuffling off into the darkness and down the slopes.

While the buffet dinner was being served, people wandered in and out of the Summit House to take in the moonlight from the deck and to witness the natural spectacle displayed before them.

This was a perfect week to ski by moonlight. A weather inversion had kept the valley under fog, while the moon and stars shone brightly above. The tops of the Swan Mountains and Glacier National Park poked up through the fog that covered the valleys, creating islands in the creamy white foam. Like a flashlight under a pillow, the lights from the cities in the Flathead Valley pulsed beneath the thick layer of fog.

To be able to ski back down in these conditions was the best dessert offered that night. Skiing under moonlight is a surreal experience best described as feeling, rather than skiing, your way down the mountain. There is no need for flashlights or headlamps. Nature is your guide. While moonlight on a clear, starry night provides ample lighting for skiing, the darkness seems to heighten the rest of your senses. When you're standing still there is no sound - only the hush of night and the hum of the chairlift in the distance. But while skiing, your skis make a gentle ripping sound as your edges weave long threads of silver on the freshly groomed corduroy slopes.

The resort's grooming machines occasionally pass you by, roaming over the ski runs like moon rovers, their headlights appearing over the horizon before the sounds of their motors break the silence. They move slowly and methodically then disappear over a ridge, leaving the smooth slopes in their wakes.

As we slowly descended, the layer of fog met us just above the village area.

We went from skiing in perfect moonlit conditions, to skiing in clam chowder with only a few feet of visibility. Where you thought the hill went this way, it went that; when you thought you were standing still, your skis were moving and you felt as if you had vertigo. One skier spun out, the ground rising up to meet his bottom, followed by a hearty laugh.

Slowly the fog lifted, revealing the lights of the village area. Turn by turn, like a plane on final descent, we made our landing and stood in silence at the bottom of Big Ravine run, looking back at the run we'd just made. Somewhere up there in the darkness, the sounds of skiers floated down under the guiding moon.

If you go: Several more Dine and Ski nights are offered at Big Mountain during full moons. Dates are: Jan. 25, Feb. 23-24; and March 25-26. Reservations are required. Cost is $25 for children, $45 adults, including lift ticket.

On the Net: www.bigmtn.com