Timbuktu. From here, America seems remote; TIMBUKTU, Fabled caravan capital still a respite from burning sands

The twin-prop aircraft takes off from Mali's capital, Bamako, and heads north along the Niger River toward the great African desert. The pilot flies low to the ground, wending back and forth across the spaghetti-like weave of the Niger's rivelets. With every passing mile the vegetation below gets sparser, sparser. The harsh heat concedes only clumps of scrawny trees to shade the occasional bands of nomadic herdsmen.

Signs of life seem to vanish altogether, when suddenly at river's bend, there breaks into view that fabled flat sprawl of desert-edge civilization that has become the archetype of earth's remotest reach - Timbuktu.

Legend has it that here, in the 12th century, wandering Tuareg nomads from the north happened upon a village with a water well tended by a local woman named Bouctou. She won the nomads' trust by guarding their belongings while they went to the desert to fetch kinsmen. Before long the site was known across the region as Tim-Bouctou - that is, the Well of the Bouctou (Tombouctou in French).

For centuries Timbuktu's ''skyline'' was the most welcome of sights to the great camel caravans that crisscrossed West Africa. The most renowned carried huge amounts of salt a formidable 650 miles from salt mines of the north Malian city Taodenit, stopping in Timbuktu before unloading cargo at docks on the Niger or pushing on to the northeast.

At their peak - in the centuries before the arrival of the French in the 1820 s - the caravans contained as many as 20,000 camels. They carried up to 3, 000 tons of salt and were escorted by 1,500 men. Theirs was a journey of 16 days through a hostile, bandit-infested desert. But the rock-salt ''gems'' they carried were more precious than gold to desert tribes to the south, for whom water retention was essential.

In time, Timbuktu also became known for its market in ivory, gold, and clothing, as well as its Islamic center of learning

But for reasons still unknown, all that fell into rapid decline. When the French arrived in 1828, the town was in ruins, a mere remnant of its earlier grandeur.

Today some breezes of the golden days still seem to blow through Timbuktu's winding streets.

To walk through the city in mid-afternoon is to be engulfed - not unpleasantly - by the same hot, dry winds and unrelenting sun that hung low from the azure-blue skies of Mali long ago.

Turban-masked merchants in black, ankle-length robes still carry out their business in the market, bartering with townsfolk over chunks of salt they've brought from the northern mines.

Little girls play in the open doorways of ancient stone buildings. The ornate metalwork of huge wood doors bespeaks more prosperous days when trading families with fabulous wealth made their homes here. The adjoining stone walls are now partially covered over with mud that is fingerpainted to look like masonry.

Meanwhile the veiled women of Timbuktu go about their daily chores, transporting huge bowls of precious water and bundles of firewood across town to keep their households going. A teen-age girl peeks over a high wall, smiles broadly, then disappears at the sight of a camera lens. Desert-bred youngsters play soccer in bare feet in the hot sand.

Since the 1970s Timbuktu's numbers have burgeoned. Nomadic peoples - many of them Arabs from desert regions to the north - have sought refuge from drought here and from the southward encroachment of the Sahara. Faces to be seen among the city's 20,000 people are an unusual assortment of Arabs from Algeria, Morocco, Libya, Sudan, and Egypt; and black African tribesmen who over the centuries have emigrated from settlements along the Niger River or farther south.

This desert outpost has not escaped the onrush of modernity - an airstrip laid in 1963, some macadam roads, a water tower erected in 1965, and electricity in 1975 to some portions of the city. The water tower became important when drought dried up 30 of the town's 40 wells, all 10 area lakes, and channels from the Niger River.

More recently, a French hotel chain, Sofitel, catapulted Timbuktu into that peculiarly 20th-century trade: tourism.

The Hotel Azalai (Caravan) sits like a sultan's oasis palace on a hill 200 yards from the city. Its irregular flat-roof architecture is a takeoff on the lines of the old city buildings. But there are added attractions: air-cooled rooms, shower-baths, hot and cold running water, and luxury dining room (though, of course, no pool).

To impoverished residents unaccustomed to seeing such comforts in the harsh desert, the Caravan Hotel must appear a very odd beast, indeed.

The heat of day breaks as evening sets in over Timbuktu. Groups of young nomads walk their camels from the market center for journeys out to camps in the desert. If you're fortunate, you can find yourself in a conversation with one of the friendlier nomads.

''What about taking us for a ride into the desert?'' some travelers ask of a new desert friend, Tarlift.

''Step right up!'' he says. Tarlift commands his camel to kneel so this writer can mount. He then ties a black turban around his own head and face, leaving only a slit for the eyes to show through.

When one is seated high atop Tarlift's dromedary on a wood-plank saddle, the undulating waves of desert dunes appear a vast white sea. The evening air is pleasantly cool, breezy, dry. The setting sun takes on a luminescent sandy hue.

Our camels weave around the occasional odd sticker tree and sagebrush. From behind the beast, a nomad hops onto the camel's spine behind my saddle, reaches around me to take the reins, and swats the groaning beast into full gallop.

''These things can run all day,'' says Tarlift, trying to keep me from falling off ot one side.

At the nomads' encampments, women are preparing meals for their families over campfires.

Of course, no visit would be complete without mats being spread over the sand , and daggers, curved swords housed in ornate scabbards, water skins, and other assorted wares offered for sale. The visitor who hopes to be re-escorted back to his home base does not feel shy about making a purchase or two.

Heading back to Timbuktu under the stars, Tarlift admits to sadness over the drastic reduction in the size and frequency of the great camel caravans. ''These days camels are replaced by the metal beast with engines that cross the desert much faster. One truck alone can carry a hundred camel loads of salt, and do in a few days what it still takes a camel 16.''

Still, he doubts that the fabled caravans and the four-footed creatures that powered them for centuries will disappear. The spirit of the desert trek still burns too strong in the hearts of hte Tuareg.

Can the nomads retain their free-ranging desert ways in the face of modernity?

''Wealthier cities to the south do have their attraction to the younger generation,'' he says. Tarlift himself sometimes dreams of what it would be like to live in a far-off mystical land like America.

''But I do not really think much about it,'' he says. ''Too remote, too remote. The desert and Timbuktu will always be home.''

Riding camelback under these friendly starry constellations of Saharan night, even an American can start to find the thought of America pretty remote.

Remote as - well, even as remote as Timbuktu.