Leticia Arguelles squints out into the blinding salt fields where she has labored since childhood. The evening sun fades, and a group of ragged workers shovels the last glistening mounds of salt into wheelbarrows.

Since before the arrival of the Spaniards in the 16th century, Colombian Wayuu Indians have harvested salt in the wind-swept region of Guajira. Today, government neglect, foreign competition and land disputes threaten to end the trade, endangering the livelihood of thousands of Wayuus.

"Salt is our way of life," said Arguelles, her leathery face covered with a brown sun cream made of mushrooms. "Without salt, our children can't go to school. Without salt, the town of Manaure will die."

With its sun-drenched deserts and strong winds, the peninsula of Guajira, on the northeastern coast of Colombia, has near-perfect conditions for salt extraction.

Early each morning, hundreds of Wayuu families, including many women and children, leave their wooden shacks to harvest salt at the mine in Manaure. Armed with shovels, picks and wooden wheelbarrows, the Wayuu salt workers brave the burning rays of the sun for hours.

Salt in Manaure is produced by evaporation. Fresh seawater is pumped into shallow ponds divided by dikes. The salt crystallizes into massive slabs, sometimes two yards deep.

The salt workers break up the slabs to reach the better-quality layers underneath. The salt is then raked into mounds and transported to the port, ready to be loaded. Most of the salt produced at Manaure is for industrial use and cattle.

Salt, one of the oldest commodities in the world, has been traded since ancient times, determining trade routes. For centuries it was used as a preservative, and the Roman army paid its soldiers in salt -- thus the term salary.

For the Wayuu, one of Colombia's 80 indigenous groups, salt is more than a way of life. It has deep symbolic and religious importance, and many of their legends have to do with salt.

About 2,000 Wayuu families depend on the salt. But this lifestyle could soon disappear.

The mine, owned by a state firm in liquidation, has been declining steadily for years. Lack of fresh investments, aging infrastructure and cheaper salt from Chile have turned the mine unprofitable, said the manager, Maria del Pilar Yepes.

In 1991, following a new constitution that recognized indigenous rights in Colombia, the government and the Wayuu reached agreement over the operation of the salt mines.

The deal called for the creation of a new salt company in which Wayuu Indians would have a 25 percent stake. The state would provide social security coverage, build a public hospital and a school center.

The agreement was largely ignored by the state, prompting condemnation by many rights groups.

Some foreign companies have been approached to invest in the mine, said Yepes. But the Wayuu, who regard Manaure and its salt mines as ancestral land, oppose privatization.

Protests at the mine have become common, and production has dwindled over the years from 600,000 tons per year to 200,000 tons.

Some experts have suggested that the economic future of wind-swept Guajira lies in harnessing wind power to generate electricity for sale to other parts of the country.

Meanwhile, Alicia Ramirez Puchaina, a salt trader, said she would continue working at the salt field until her last day.

If the mine closes, she said, the Wayuus will turn to smuggling. Poverty, lawlessness and a trading tradition that goes back to the days of English and Dutch pirates have turned Guajira into a smuggler's paradise.

"I have worked in this salt field since the day my mother brought me. We are not leaving the salt fields," she said.

Leticia Arguelles, a Wayuu Indian salt worker, wears a cream made of mushrooms to prevent sunburn.A Wayuu pushes a wheelbarrow full of salt at the Manaure mine. Indians have harvested salt in the wind-swept region for more than 400 years.A woman takes a break during a workday at Manaure. Salt farmers, including women and children, brave the burning rays of the sun for hours.Wayuu Indians leave the salt mine in Manaure, northern Colombia, at sunset. Official neglect, foreign competition and land disputes threaten the trade.