A Mexican Icon: since before the time of Cortes, towering volcano Popocatepetl has inspired awe and worship.

"There they were, the two monsters, watching gigantically and terribly over this lofty, bloody cradle of men, the Valley of Mexico. Alien, ponderous, the white-hung mountains seemed to emit a deep purring sound, too deep for the ear to hear ... murmuring like two watchful lions."

D.H. Lawrence, "The Plumed Serpent" (1926)

Anyone driving from Mexico City south toward Cuernavaca and Acapulco, or east toward Puebla and Veracruz, has seen the volcano alert signs: Two jagged mountains--one pointed--and the warning that we are currently in "Amarillo 2," the highest stage of yellow alert.

This emergency phase warns the public not to come within 12 km of the crater of the gargantuan, active volcano called Popacatepetl.

The 17,945-foot mountain, Mexico's second-highest peak, is both a deity to those who live in its shadow and an icon for the Valley of Mexico.

Locals call it "Don Gregorio" and have constructed altars in its honor, enacting rituals to appease its wrath. The twin white peaks of Popocatepetl and its neighbor Iztaccihuatl have come to visually represent the Valley of Mexico, and they appear in centuries of colonial paintings, famous works of Mexican muralists, contemporary art and advertising.

Popo, as Popocatepetl is commonly known, in particular has dominated perceptions of Mexico since the European conquest and before.

A CONQUISTADOR'S IMPRESSIONS

In October 1519, when Spanish and indigenous armies left Cholula, in modern-day Puebla, for Tenochtitlan, crossing the Ahualco mountain range at a point now known as the Paso de Cortes, the Spanish conquistador was shocked to see an enormous black cloud rising toward the heavens like "a large house." Later in the 16th century, colonial chronicler Toribio Motolinia compared the column of smoke from Popo to the tower of the Seville Cathedral.

The oldest historical record of this conical-shaped volcano dates to the period when it was first given its name. It used to be called Xaliquehuac (meaning "sands that rise"). But in the year 9-cana of the Aztec calendar, which corresponds to 1347, the volcano erupted so spectacularly that Nahuati-speaking people, or Aztecs, began to refer to it as Popocatepetl, or "smoking mountain."

Even from a non-mystical perspective, the mountain has earned its godlike status. It is a crucial source of water--according to Environment Secretariat (Semarnat), the forests surrounding Popo and Iztaccihuatl contain 40% of the Valley of Mexico's underground water and provide oxygen for Mexico City and Puebla.

It is also a shelter for wildlife--eagles circle its heights and pumas pace its flanks. Inhabitants include lynx, deer, foxes, the short-eared "teporingo" rabbit and the "volcano mouse," a rodent that can withstand intense cold. It is a paradise for bird watchers with 70% of the bird life that is associated with volcanoes present in the area.

POTENTIAL FOUNTAIN OF DISASTER

In addition to being an ecological treasure trove and a magnet for clouds, storms and lightning, Popo also vibrates with potential threat, making it a natural counterpart to that chaotic cluster of more than 20 million people in and around Mexico City that has become synonymous with environmental woes.

With nearly 30 million people living within view of its peak, Popo has been called the world's most dangerous volcano. A spectacular eruption in December 2000 had the scientific community raving at what they believed was Popo's biggest explosion in a millennium.

But in Mexico City, Puebla, Amecameca (the nearest major town to the volcanoes) and even Veracruz--where volcanic ash is often carried by winds--inhabitants were hardly amused.

While vulcanologists were stammering with excitement on news programs about the "stromboli effect," which resembles a firework display at the crater and hadn't been seen in centuries, millions were staring anxiously at the television, noting how one side of the crater had started to erode with the eruptions. People pored over local newspapers to learn emergency precautions, often printed on the front pages, such as covering water sources that would be contaminated by volcanic ash.

Planes were diverted, as the international airport came to a temporary standstill with fears of obscured vision and volcanic ash choking aircraft engines. The words "incandescent material" became the pet phrase in media reports and radio chat shows.

More than 300,000 people live in the danger zone directly under the volcano and three villages received evacuation orders, with the army coordinating rickety buses to cart thousands of people to shelters in Mexico City. A few refused to abandon their livestock with no one to feed them. Others were reluctant to leave their homes fearing looters would steal their scarce possessions.

One evacuated site was Santiago Xalitzintla, seven miles from the crater on the volcano's northeastern flank. Villagers were told their homes would almost certainly be wiped out by the avalanche of sludge and acidic gases surging down the canyons at more than 60 mph, which was likely to accompany a major eruption, even before the lava reached them.

After spending fitful nights in makeshift camps, many locals--homesick for their place in the shadow of Popo--defied the warning and returned home before officials gave the green light.

AN EVACUATION CRITICIZED

Two years later, leading conservationists and townsfolk from Amecameca are still critical of the evacuations in 2000.

"History shows us the volcano has done this 13 times," said Alejandro Lopez, anthropologist and Director of the National Commission for Protected Areas (Conanp).

To counter the atmosphere of fear and avoidance, Popo defenders tell the colorful history of social human interaction with the volcano.

Local folklore weaves a mystical tale of awe and respect in the granizeros--shamans or rainmakers--who were once struck by lightning and whose destiny thereafter is to communicate with the mountain. And there are also riveting stories of mountain heroics. For instance, the legendary local climber known by his moniker El Tlaxquiche climbed both volcanoes countless times in his shorts and T-shirt, saving lives on occasion and receiving a round-the-world trip in gratitude from French hikers, who set up a statue in his honor back home.

"Popo has been active for at least 600 years, usually at around 50-year cycles," said Lopez, who is pushing National Disaster Prevention Center (Cenapred) officials for a reduction in the alert to Yellow 1 from its current level of Yellow 2. Such a move would allow the public to come within 6 km of the crater, and it would prove economically beneficial to local communities.

Before the current cycle of activity that began in December 1994, Amecameca, which is located in the State of Mexico, was a popular stop for people hiking up to Popo's peak. The climb was exhilarating and not too arduous, as long as you didn't suffer from altitude sickness. The snow-encircled crater even offers a warm, vibrant green lake in which hikers can swim.

But with the new active phase, the army has sealed off the routes, and the public is prohibited from climbing Popo. Villagers often have trouble accessing fields to harvest their maize. Reports and spectacular photos of the plume of ash became regular features in Mexican newspapers and tourism plunged.

"From over 500,000 visitors per year in the '70s, now the Parque Nacional Iztaccihuatl-Popocatdpetl sees less than 50,000 people per year," Lopez said. "Tourism has fallen by 90% and people who worked in the tourism industry are now scraping out a living by extracting natural resources."

While he said illegal logging is a bigger problem in the north of the state, it is still an issue in the skirts of the volcanoes. Forest fires have also eaten almost nine hectares of forest in the last 15 years.

Conanp has managed to reduce forest fires by 90% and is working on a bio-literacy project as part of its work in environmental education, targeted at children aged six to 11. With financial support from Grupo Modelo and other business corporations, and with the help of the army and rural communities, the commission has planted some 2.5 million trees in an area of nearly 2,000 hectares and dug tinas ciegas, which is a technique for capturing water.

If you visit Amecameca now, the decline of tourism is immediately visible, with large empty restaurants and decaying hotels in the area known as Popo Park.

Inhabitants and local business people still bristle at being abandoned by authorities, asking why the volcano isn't promoted as a tourist attraction, as are active, erupting volcanoes in Costa Rica and Hawaii. Others consider themselves victims of sensationalist newspaper coverage.

"The journalists came in December 2000 and took thermo photos and made the lava, that looked gray to the eye, bright red," said Miguel Angel Reyes, manager of the formerly fine hotel Los Volcanes, 20 km by road from Popo, but 10 km from the crater in a direct line. "They also enlarged the boulders that flew from the mouth of the crater to make everything seem more dramatic."

Reyes says he says he never felt threatened, even in 2000.

"I feel comfortable with the volcano. The activity is very moderate for the mountain's size and force--it's as though it is smoking a cigarette."

Talking on a cloudy day, when neither Popo nor Iztaccihuat1 are visible, even this close to the crater, the notion of explosions and danger indeed seem a product of a fevered imagination.

But reaching the Paso de Cortes, the path between the two volcanoes the conqueror took on his triumphant march to Mexico City and 7 km from Popo's crater, it is hard not to feel an adrenaline rush. Although officially against the rules, transit is permitted but drivers must show ID and reassure soldiers at the roadblock they are only visiting for a short time.

Further up, in the "high-risk" zone, which can only be visited in the company of an accredited official, it is hard to doubt one is in the presence of the supernatural. Laboring up the slopes over gritty, almost sticky gray volcanic sand, one's cheeks burn in the radiant sun. White, pink and charcoal pumice stones lay scattered, giving the sensation of a diabolic moonscape. With a heart beating like a tickertape machine from the unaccustomed altitude, you may hear Popo roar from its depths, a menacing and elating sound.

FLIRTING WITH YELLOW I

Last year, volcanic activity declined noticeably.

In November 2002, Cenapred and security officials were poised to decide whether the alert could be reduced. But, with a new lava dome forming, the decision was postponed until the end of January. It was further postponed after a quake on January 21, centered far away in Colima but affecting the Valley of Mexico and keeping Cenapred officials busy.

The decision, if it comes, will allow Conanp to open the Iztapopo National Park with a visitor's center and three different paths for hiking and bird watching.

This would help rejuvenate tourism in an area fertile with waterfalls, trees, lakes, churches, haciendas and other unique places of interest. Located just one hour away from the capital via the Puebla Highway, the stunningly situated park would opening the doors to eco-touristic ventures that Mexico wants, and needs, to promote.

The park, a verdant pine forest, already includes various environmental initiatives, and new paths and picnic areas are being set up. The government has established a website, www.iztapopo.gob.mx, to keep the public updated on developments.

POPOBIPS AND POPOCAMS

So the question lingers: Is it safe?

Forty miles from the capital, Popo is the most closely monitored of Mexico's 14 active volcanoes. A special unit of vulcanologists and seismologists keep a 24-hour watch on its every mood, and are considered to have one of the world's best volcano monitoring networks.

State-of-the-art equipment includes four seismic sensing stations on the volcano's flanks and a "tiltmeter" to detect minute alterations in the slope of the volcano, which swells when magma rises into it. Additionally, an "acoustic-flow monitor," sensors to pick up shifts in gases, electrical and magnetic fields and special detectors to listen for "harmonic tremors," or earth vibrations set off by moving magma, are also watched carefully.

There is also a network of "Popocams", video cameras hooked up to the Internet, which keep vigil over the smoking mountain (click on "Imagen del Volcan" at www.cenapred.unam.mx/mvolcan.html).

Currently 120 people--scientists, government workers, park officials and local authorities--walk around with a device called a "Popobip" that starts beeping when the level of alert increases. Popobips also receive a report every day at 11 a.m. from Cenapred, which details the amount of exhalaciones (emissions of sulfur dioxide, ash and rock) and micro-sismos (small tremors) registered over the past day. For most people in Amecameca, this is enough.

"We can't just freeze up. The volcano wants to be in peace," said Lopez

Barbara Kastelein writes about Mexico travel and tourism far Fodor's Travel Publications, Conde Nast Traveller (UK) and the Sunday Express news paper of London.