Argentina’s Sophisticated Resort for All Seasons : Mountain city of San Carlos de Bariloche is in South America, but it could be Aspen or Zermatt.

When summer’s heat fries the soul, wealthy South Americans head for the cool slopes of the Andes, and a favorite destination is Bariloche, the sophisticated resort city in the heart of Argentina’s magnificent lake country.

Snuggling the shoreline of beautiful Lake Nahuel Huapi, 60 miles long and the deepest of blues, Bariloche blends gorgeous mountain scenery with lots of sun-splashed outdoor activities and some of the finest vacation lodging and dining on the continent. If you are touring South America, as we were last March, it’s a fine place to settle for a few days to catch your breath.

Two comparisons leap to mind: Aspen, Colo., and Zermatt, Switzerland, both famous winter ski resorts that are almost as exciting when the snow melts. Bariloche, too, is an international ski center, drawing Americans and Europeans south of the Equator when the lifts at home shut down. In the summer, it fills with hikers, backpackers, cyclists, boating and fishing enthusiasts, water skiers and plenty of less-athletic sightseers, who watch the bustle from their tables at sidewalk cafes. They are a trendy bunch, these South American vacationers, appearing day and well into the night in the most chic European fashions.

One difference, however, is that Bariloche--the full name is San Carlos de Bariloche, although nobody calls it that--is a big city, several times larger than Aspen and Zermatt. But its size is no great drawback. You can get almost anywhere within the city center on foot, and that beautiful lake is never out of sight.

Bariloche exudes Old World flavor--with an alpine accent. The streets are lined with chalet-like buildings, giving the city the quaint look of a Swiss village. Even the town clock, at the top of a stone tower, is very much Swiss. When it chimes the hour, four mechanical figures emerge from the clock--in this case, an Indian, a Spanish conquistador, a missionary and a worker, each representing an important aspect of Argentina’s heritage.

And should you not yet be convinced that you have strayed into the Alps, just take a sniff of the air. The aroma, wafting through the streets on lake breezes, is chocolate, a product for which Bariloche is also famous. Every downtown block seems to house at least one large candy shop featuring a variety of its own homemade chocolates. The local chocolate is so highly regarded that several days later in Paraguay, I was able to buy a chocolate ice cream cone made with what a big sign boasted was “real” Bariloche chocolate.

About 800 miles southwest of Buenos Aires, Bariloche is easily reached by good highways, first-class train and bus service and frequent jet flights daily from the capital. From Bariloche, you can cross the Andes by lake ferry and bus to southern Chile, a full day or overnight excursion featured on many South American tour packages. We arrived from Chile over this route, and then flew on to Buenos Aires, a two-hour flight, after our stay in Bariloche. South America’s seasons are just the opposite of ours: It is now spring there, with the warm summer months ahead.

The city sits just at the foot of the eastern slope of the Andes, like a hiker taking one last rest before making an ascent of its soaring, snow-tipped peaks. Many city streets are quite steep as they climb from Lake Nahuel Huapi, but less than a dozen miles east of town, the municipal airport occupies the dry, flat plains of Patagonia. For all its scenic appeal, the lake itself is rather oddly shaped. Sculpted by ancient glaciers, it resembles a slender, wiggly water bug with lots of arms outflung.

The city and the lake are part of Nahuel Huapi National Park, one of South America’s oldest and most majestic preserves. A city such as Bariloche within a national park is a strange concept to U.S. visitors, since development in American parks is strictly limited or banned outright. In its urban aspects, however, Nahuel Huapi more closely resembles Canada’s giant Banff National Park. When both were created, the prevailing idea was to tame the wilderness as a vacation playground, as well as to protect it.

Tame it is around Bariloche, but the resort is a jumping-off place for day trips by car, tour bus, bicycle, excursion boat and foot into a rugged mountain realm of cold lakes, rushing streams, densely forested slopes and craggy mountaintops high above the timberline. The park’s tallest mountain, Mt. Tronador, is an extinct volcano that rises to 11,722 feet. Its name, translated as “Thunderer,” comes from the crashing sound of ice walls tumbling from the glaciers that cling to its three peaks.

A popular but difficult 50-mile drive climbs to one of Tronador’s glaciers, where waterfalls spill in a misty spray that nourishes hanging gardens of wildflowers. Less of a challenge is the daily boat trip to Isla Victoria in the center of Lake Nahuel Huapi to see a forest of the rare and curious tree called the arraya’n. Found nowhere else in the world, its russet-hued trunk grows in gnarly twists, and its bark sheds in curly strips like a eucalyptus. The effect is strangely sinister, and the tree is said to have been the inspiration for the scary forest in the Walt Disney movie “Bambi.”

We spent one gorgeous afternoon at Puerto Blest, at the tip of Lake Nahuel Huapi’s westernmost arm, where the lake carves deepest into the towering Andes. On the far side of the lake, giant rocks thrust from the forest like jagged teeth. But don’t get the idea that you have arrived in absolute wilderness. As in the Alps, the southern Andes are dotted with fine mountain lodges. The Hosteria Puerto Blest, a solid, two-story stone structure topped with a heavy log roof, stands on a grassy knoll above the dock. Its gabled roof is alpine in appearance, and the array of flags flapping in the breeze gives it a festive air. The lodge offers a full four-course lunch with wine and beer, served by tuxedoed waiters in a large and formal dining room.

I am a skier, so I wanted to see Bariloche’s downhill slopes, although in summer they are covered in grass. A bus shuttles hourly between downtown Bariloche and Cerro Catedral, Argentina’s major ski center. The bus ride takes about half an hour, and the route hugs the lake’s shoreline for a few miles before turning inland for the steep climb to the ski area. A couple of lifts are kept running in summer for sightseers, and the view of the lake from the top is superb. Instead of seeing skiers, we watched a herd of horses galloping down the mountainside.

Our first night in Bariloche, we chose a restaurant called Casita la Suiza, an intimate inn of charming Swiss decor, where we ordered local trout, which was nicely baked. Another day, we ate a leisurely lunch at El Viejo Munich, which is decorated in deer antlers and the dark carved wood of Bavaria. It features goulash, sausages, hot potato salad, fresh beet salads and hefty steins of good beer. The pace of lunch is very leisurely, because--more Latin than alpine-like--almost everything else shuts down at midday for a couple of hours.

But enough of Old World menus, we said. On our final night in town, we headed for a real Argentine-style steakhouse, the 9 de Julio, near the top of one of the city’s steepest streets. Nicely grilled on a charcoal fire, my hunk of beef covered my entire plate, and I didn’t quite manage to finish it. Food is moderately priced in Argentina, and a full dinner for two with drinks and tip came to about $40 each night.

Incidentally, in Bariloche--as in much of South America--most diners don’t show up at restaurants until 9:30 or 10 p.m. One night I noticed a youngster napping at his table. Before my meal was over, just shy of midnight, I knew exactly how he felt.

Part of the summer fun at Aspen and Zermatt is browsing through the shops, and Bariloche has a similarly spiffy array of boutiques on Calle Mitre, the main street. Several carry expensive European imports, but bargains are to be found. Argentine leather goods and hand-knit wool sweaters in fashionable colors and designs are among the better buys. Brightly painted ceramics are another of Bariloche’s famous manufactures.

GUIDEBOOK

San Carlos de Bariloche

Getting there: From Buenos Aires, Aerolineas Argentinas and Austral, an Argentine airline, offer nonstop one-way service to San Carlos de Bariloche for $226. Through June 20, American Airlines and Aerolineas are quoting round-trip fares of $1,546 from LAX to Bariloche.

When to go: The summer resort season in Bariloche is December through February.

Where to stay: Bariloche offers a variety of lodging, from modest bed and breakfast inns to luxury hotels and attractive lakefront chalets on the road between Bariloche and the Llao-Llao peninsula, 16 miles to the west. Two very good lakeview hotels in the city are the Edelweiss and the Chamonix. The rate at the Edelweiss, listed as a five-star hotel, is about $85 a night for two people. We stayed at the much more modest Interlaken Palace, where the rate was about $52 a night for a lakeview room.

Where to eat: Again the choice is wide. Local lake trout is a staple. And the Argentinian restaurants serve grilled beef in a variety of cuts. A full dinner for two is about $40 with beer or wine, tax and tip.

For more information: Contact the Argentina Government Tourist Office, 3550 Wilshire Blvd., Suite 1450, Los Angeles 90010, (213) 736-5232.