We plodded on, two or three hours longer and at last the lake burst upon us -- a noble sheet of blue water... walled in by a rim of snow-clad mountain peaks... I thought it must surely be the fairest picture the whole earth afforsd .

Mark Twain, from "Roughing It"

I was here only one day and got a thank-you note from my lungs. They enjoyed breathing so much they wanted to know if it was legal .

Bob Hope

LAKE TAHOE, Nev./Calif. -- Two humorist, 100 years apart. Yet each spoke of this, the second largest lake in the world at its altitude, in glowing terms. Is Tahoe really that specatacular? Is it still the prisline jewel that Twain described? And is the air still as clear as Hope found?

With a few exceptions, the answers are, happily, yes. Lake Tahoe is still the most stunning sight in these United States, in my opinion. The windig, climbing, mountain-hugging road around the lake is still perhaps the world's most spectacular. And now, while winer lays an ever-deepening blanket on an already quiet countryside, is the time to see Tahoe.

For in the summer, Twain's "fairest picture the whole earth affords" is often cluttered by discarded Polaroid film packs and Kodak film boxes as million (the lake area attracted more than 9 million visitors last year) of camers-burdened tourists snap away. Winter is the time to visit Tahoe, the time to appreciate its beauty, the time to be invigorated by its sun-baked ski slopes and its shimmering, dark blue water -- a perfect mirror for the High Sierras surrounding the lake.

For skiers used to Colorado and its long lift lines, Lake Tahoe is as invigorating as a hot rum todayh at the end of a two-mile run down a slope of pure power. Lake Tahoe is the ski capital of Northern Dalifornia, and rivals Colorado for variety and quality of the slopes.

Among its 22 ski resorts, Tahoe numbers world class slopes. Like Squaw Valley, site of the 1960 Winter Olympics, where 25 lifts will take you to score of slopes, and Heavenly Valley, billed as the largest ski resort in the Unied States, with more than 20 square miles of skiing split betwen California and Nevada. Heavenly will host the World Cup Races in March this year and participants (and you, too) can choose from being transported by the resort's tram, one triple chair, 14 douple chair lifts or nine other lifts. Or you can (for a cool $140 per person, per day) take Heavenly's helicopter back into the High Sierras and ski where only the angels go. (Squaw Valley day rates: $14 for all day. Heavenly: $14.50).

But Tahoe is probably better known for its family ski resorts. Small places like Homewood, which offers reasonable rates (an adult all-day ticket is only $10, $8 midweek), an excellent ski school and three major ski lifts: Madden Ridge (double chair), the Quad (four-person chair) and a long T-bar up to "The Tailings." And, as a bouns, you get one on the most spectacular views of Lake Tahoe from the area. Or try North Shore, between Truckee and North Lake, Tahoe, where you'll find 1,100 acres of protected ski runs serviced by six double and a new triple chair lift. North Shore has an extensive ski school and gentle runs on which to learn.

The new favortie with local skiers, the one with shorter lift lines, the best snow, and the best skiers, is Kirkwood. Although it is a 45-minute drive from the South Shore, its relative remoteness makes it the jewel of Tahoe skiing. It sist on the western slopes of the Sierras at a base elevation of 7,800 feet, which produces very dry snow and lots of it. It is probably the best powder skiing in California and the lines are nearly non-existent, except on special weekends. Kirkwood has eight chair lifts with lift ticket prices set at $13 for adults and $5 for children. The area has 25 percent of its runs for beginners, 25 for advanced skiers and the rest for intermediates. It is particularly popular with local skiers because they don't have to put up with all the outlanders from San Franciso.

Skiing is not the only attraction keeping Tahoe's economy alive, of course. There is something else -- a little thing called gambling -- that accounts for the immense popularity of this area, even in the winter. Where else in the United States can you spend a day sliding along on those funny little boards in the snow and then spend the evening sitting beside an Arab betting $1,000 a draw at baccarat?

Stateline, Nev., an unincorporated area sittig beside South Lake Tahoe, Calif., is the gambling center on the lake (and a five-minute drive from Heavenly Vally). Only an hour's drive from Reno (take a bua, or limo for $6.50, or rent a car), Stateline offers the same gambling joys as its larger brothers like Las Vegas and Reno, but with a certain charm missing in the big casinos to the south.

Friendliness and youth are the hallmarks of gambling in Lake Tahoe. There is a much higher percentage of women dealing blackjack in Tahoe than in Las Vegas and it has become a trademark of gambling in northern Nevada.

"It started at Harold's Club in Reno as far back as the '40s," explains Tom Yturbide, a casino official at Harrah's. "Now it's trademark of gaming in northern Nevada. Most of our dealers are women, and they are trained to be friendly and to make eye contact. Everyone who sits down at a blackjack table gets a frinedly smile from the dealer."

"It has nothing to do with Women's Lib," says a long-time pit boss. "It's just that people don't mind as much losing to a pretty girl."

Another difference in Tahoe is that the small roller isn't scared off. "We do most of our business with dollar bettors, and we try to be a little more friendly," says Loyal Borden, a Sahara shift manager who has been at Tahoe for 20 years. "We won't run off a $2 bettor to make a high-minimum table. We hire a lot of young people and make our customers feel at home."

As one ski-sweatered man told me as he pointed to an attractive baccarat dealer. "I watch her smiling and flicking those cards, and I can't help thinking I'm not being cheated. I'm used to Vegas with a haggard old dealer with bony fingers. This place is something else. I can't believe it."

And winter is also the best time to visit the casinos, as well as the rest of Lake Tahoe. In August, the patronage in the casinos may be as high as 70,000 people a day. But October through May things quiet down and the casinos are restful. Oh, the rumbling of slot machines is maddening, the slap of cards on green felt continues, the shuffling of voices at times overpowering, but it isn't at the frantic pace of the big Vegas places. And, on top of everything else, the top-name entertainment continues all winter, so you can see Willie Nelson, or Lou Rawls, or Chicago, or Crystal Gayle as a bouns.

Two of the big-name casinos are here: Harrah's, perhaps the most sophisticated, with rooms that feature twin baths complete with television (they cost $100,000 each to construct), big-name entertainment and the area's top restaurant, the Summit; and Del Webb's Sahara Tahoe, which has more convention trade than the others, 1,200 slot machines, and more star enterainment. Also at South Lake Tahoe are Harvey's and the just-opened Park Tahoe. At the north end of the lake are the Cal-Neva Lodge, one of the most historic locations on the lake and a former property of Frank Sinatra, who owned the lodge in the early '60s until Nevada gaming officials banned his participation, and the Haytt Lake Tahoe at Incline Village, which offers -- at Hugo's -- the north shore's finest dining. Incline Village is also the location of the most expensive building sites on the lake -- starting at $125,000 for a 50-by-100 lot.

But the real action is at the south shore and its more sophisticated, more posh clubs. And with all that action comes the greatest problem Lake Tahoe faces: people and people pollution.

South Lake Tahoe has one of the ugliest strips of any resort area in the United States. Here, amid the towering pines, soaring peaks and the deep blue, sparkling water of Lake Tahoe, is Neon City. "Hot Tubs," "Madame Juanita will read your palm," "Hot Tubs and Water Beds," "Enjoy our Goofy Golf," "Hot Tubs and Water Beds and Adult Movies," "Marriages arranged: Flowers and Pictures Included," "Hot Tubs and Water Beds and Adult Movies and Stain Sheets." All this on Route 50 in South Tahoe and it does take the edge off the beauty of the lake.

But there is hope that this, too, is changing. The South Lake Tahoe City fathers have realized that shlock is no attraction and have taken steps to stop the growth of the trash: All signs have to be changed to wood within the next year; if you want to cut down even one tree, it may take you up to six months to get a permit; no major commercial structures have been built in South Lake Tahoe in the past five years and those that are on the main street are being forced to clean up their exteriors.

On the other side of the line, in Stateline, Nev., environmentalists are equally as strong. It took the owners of the new Park Tahoe seven years to complete the casinos, thanks mainly to strong objections from the Sierra Club and other. The guest rooms in the new casino and hotel won't be ready until late this year.

"I seriously doubt there will be another casino built here," says Bob Anderson, of the South Lake Tahoe Visitors' Bureau. "It would take them 20 years to get all the necessary permits."

(The Legislatures of California and Nevada are seeking agreement on amendments to the existing bistate compact on Lake Tahoe, which would prevent additional gamgling casinos in a move to protect the environment. The federal government is also involved. After the states have approved the measure, Congress is expected to act on legislation to permit the Forest Service to buy two proposed casino sites on the Lake's south shore.)

And that is just fine with most people, who are against all the development that has already spread along the lake. Fortunately, 62 percent of the land surrounding the lake is in public hands, so development is limited.

Let's hope we can always think of Lake Tahoe in the terms of conservationist John Muir who, in the last century, said, "For my part I should like to stay here all winter, or all my life or even all eternity. And so, Mr. Muir, would I -- at least in the winter.