Fanatic skiers pride themselves on their willingness to ski any time, anywhere, any place. Arctic cold? We're out there with face masks on. Tornado-like winds? Two extra sweaters. Yucky snow? Time to work on technique, we rationalize.

But what do you do when the snow is worse than yucky? Or when you have just wrecked your knee?

One answer is: Go crazy. There are, however, more reasonable alternatives, as I discovered late last spring. I had sprained my knee on the second day of a vacation in Colorado. At the same time, 70-degree sunny weather was turning those beautiful white stripes on the mountain into flumes the color of chocolate.

Because I had a "fly-or-die" airline ticket, as a friend calls the non-changeable fares, I was locked into a week's stay at my Snowmass Village condo.

The second most popular winter sport in Snowmass and Aspen is shopping, but I'm a low intermediate in that department and Aspen prices are strictly black diamond. So after one stop at the Unicorn bookstore for a 600-page spy thriller, I decided to seek more creative substitutes.

Snowshoeing, suggested my pal Cheryl. Buttermilk Mountain, Aspen's flattest ski area, still had a marginal snow cover and its pitch is quite gentle. It's fun, she said. Economical too: If you walk uphill, rather than use the chairlifts, you don't have to buy a lift ticket. With an Ace bandage on my knee and a pair of borrowed snowshoes, I joined Cheryl at the base for a nice stroll up the hill.

I never realized how challenging Buttermilk could be until I spent my first 15 minutes tromping up it on those funny-looking lacrosse baskets strapped to my sneakers. Among aerobic addicts, snowshoeing is quickly becoming as much of a winter fad as roller-blading is in summer, and I was learning why. My sea-level lungs were bellowing, despite the gradual incline and the snail-like pace that Cheryl, who lives year 'round at Aspen's 7,900-foot altitude, had thoughtfully established.

In a parking lot, snowshoeing seems like a snap. There's no great skill to learn; if you can walk, you can waddle on snowshoes. We even carried ski poles to help balance ourselves, as well as to add an extra thrust to each step. Start stepping uphill, however, and a baby slope suddenly looms above you like Aconcagua.

After about half an hour, we had a nice, heart-thumping rhythm going. As she listened to my labored breathing, though, Cheryl grew worried. Not only was she afraid that I might pass out, she thought I was hating the entire experience.

"Oh, no! (gasp) This is really (gasp gasp) great!" I insisted. And, in its own sadistic way, it was. It was remarkable to approach a ski mountain from the opposite direction. Of course, I was going to die soon, but I've always believed a person should expire in one's favorite environment.

As we reached the half-way mark -- Buttermilk measures 2,030 from bottom to top -- two other snowshoers, chatting merrily, jogged past us so fast they barely had a second to say hello. I was awed by their cardiovascular superiority.

We had nearly reached the top of Buttermilk when the sky clouded over, giving me the perfect excuse to turn around. Trotting downhill was a gas; I felt like a 10-year-old again, awkwardly stumbling down the snow-laden hill behind the Brooklyn Museum. Whoops! These things can get slippery, I laughed, as my legs shot out from under me and I fell.

The visual perspective was as interesting going down as it had been going up. Even with ski poles, I now realized that baby-faced Buttermilk has a decided pitch to it. When you are on snowshoes, instead of skis, you re-live those first fearful ski-school moments you thought you had overcome.

Back in the parking lot, I thanked Cheryl profusely for introducing me to this wonderful winter activity, drove home and took a very long nap.

The next day, my strained knee grounded me. Otherwise, I might have given the snowshoes another go (on a level trail high in the woods, rather than up a mountain). Or I might have tried ice skating at Aspen's indoor Ice Garden. Another alternative? Mud biking on a mountain bike, a wonderful adventure for those who revel in getting filthy. If I had been closer to Glenwood Springs, which is 40 miles from Aspen, I could have participated in the ultimate adventure for those who prefer getting clean -- an afternoon soak in an enormous swimming pool fed by natural hot springs.

I had gone hot air ballooning once, and would have again, if I had planned a few days ahead and lined up friends to join me. The sensation of floating upward at sunrise from the snow-covered Snowmass golf course into a cloudless cornflower-blue sky is unforgettable. And gazing at the mountains from a basket suspended from a huge balloon is far more lovely than looking at the same scene through the window.

Unfortunately, my knee problem precluded a wilderness trip, a choice I might have made even if the downhill skiing conditions are acceptable. Either with friends or with an organized group and guide, I would have driven high into the Sawatch Range between Aspen and Vail, where you are still apt to find good snow cover above 9,000 feet, for a cross-country ski tour along the Tenth Mountain Trail.

In recent years, I have made several exhilarating "hut-to-hut" trips, in which you trek through forests on marked trails and stop for the night in remote cabins built for that purpose.

Hut-to-hut skiing has a long tradition in the Alps. Now, Americans can enjoy the same kind of back-country expeditions in Colorado, Idaho and the Adirondack Mountains of New York, among other places.

From what I have seen, the Tenth Mountain Trail is the most extensive as well as most deluxe of the U.S. systems. It includes 16 shelters ranging from true inns (read: flush toilets) to rustic, ruggedly handsome log cabins. There are more than 300 miles of trails. The huts are an average of seven miles apart, tucked far away from paved roads in gorgeous mountain settings.

Skiing hut-to-hut on the Tenth Mountain Trail can be tough or easy, depending on snow conditions, your cross-country skiing ability, your comfort levels on ungroomed routesand your stamina. Most skiers use sturdy boots and metal-edged back-country skis that are wider andsturdier than standard track skis. Typically, you carry your clothes and sleeping bag on your back in a pack. Some huts have regular beds and some private rooms, others have dormitories with mattresses.

Even if you get caught in a blinding snowstorm, as I once did, a good guide will make sure everyone finds that evening's shelter. Once you arrive, the effort spent getting there, the knowledge that you are together in the middle of the woods a long way from "civilization," and the shared living conditions tend to spark easy friendships. A hut-to-hut trip is like camping out, except you don't have to worry about building a snow cave or freezing inside a tent.

Alas, on this trip I was deprived of the hut hike option. Instead, trying not to daydream about a healthy knee and a magical snowstorm that would dump two feet of fresh powder on the slopes, I decided to time-trip into Aspen's past. I visited the one remaining silver mine open to tourists.

Many Aspen vacationers have no inkling that those cute restored Victorian houses in town, now priced at up to $1 million or so, were once the cabins of miners who toiled in tunnels hidden inside the very mountain upon which we now ski.

The Smuggler mine is located a few minutes' drive from the center of town on a hill overlooking the Roaring Fork Valley. None of the standard guidebooks mention the mine tour; I happened to read about it in a local newspaper. I was intrigued by the idea.

From the entrance you can see both Aspen Mountain, which still contains numerous mine shafts way below the ski lifts, plus Red Mountain, which is covered with one of the most concentrated collections of millionaires' homes outside of Palm Springs. The view sort of encapsulates Aspen history in the blink of an eye.

My guide, Jay Parker, met me out front, his face properly smudged with grime, a hard hat and miner's lantern on his head. Since I was the lone tourist that afternoon, I got a fascinating one-on-one history lesson during the next hour for $15.

As we climbed into a tunnel, Jay, himself a miner, noted that in the 1980s and 1990s, while Smuggler yielded up hundreds of thousands of dollars for its owners, the men who did the subterranean work were paid $3.50 a day for a 12-hour shift. Pretty good pay, he hastened to add, in an era during which many working people elsewhere were happy to earn $1 a day.

Inside the mine it was, as the song says, dark as a dungeon and damp as the dew. Jay told me how the miners worked by candlelight, gestured with his flashlight at holes drilled for explosives, and demonstrated how workers would follow a vein to the rich ore.

By the time we emerged from Smuggler, it was night. The lights of modern Aspen flitted below us. But it didn't take a great leap of the imagination to picture the town in its original heyday, when silver, not snow, brought boom times to this remote mountain valley. That night I chucked the spy thriller in favor of a book on Colorado's mining frontier days.

While an injury and a bad snow week often can be a bummer to a downhill ski fanatic, I learned that they can also allow you to expand your winter horizon.

Grace Lichtenstein, a former Rocky Mountains bureau chief for the New York Times, divides her time between Manhattan and Snowmass Village.

Among Aspen's winter options away from the ski slopes:

Snowshoes cost from $65 to more than $100 per pair. Bindings are extra. A few shops in the ski resorts rent them.

Hot-air ballooning: Adventures Aloft, 303-925-9497, and the Unicorn Balloon Co., 303-925-5752, are two of the outfits that lift off regularly in the Aspen area. The cost is about $150 per person.

Hut-to-hut ski touring: Contact the Tenth Mountain Trail Association, 303-925-5775, for information -- including the names of guides and details on shuttle serviceto trailheads -- and hut reservations. Rates per night at the huts range from $20 to $27 per person, with higher rates at three ranch inns along the trail.Mine tour: Tours of the Smuggler mine, which last about an hour and cost $15 per person, are by appointment only. To schedule a visit, call the Smuggler Consolidated Mines Co., 303-925-2049

Hot springs pool: Glenwood Springs' pool complex includes a restaurant, bar and lodge. Call 303-945-7131 for fees and information.