If you look at a detailed map of Mexico, just southwest of the spot where the Mexican states of Coahuila, Chihuahua, and Durango meet, you might see an area called "Zona del Silencio," or "Zone of Silence." It's part of the Bolson de Mapimi, which is in turn part of the Chihuahua Desert. 1000 million years ago the area was beneath an ocean, but today it's a forbidding desert where daytime high summer temperatures have reached a reported 122 degrees F.

The Zone itself doesn't have well-defined borders, and tends to move around depending on who's talking about it. Most sources confine it to Durango, but some extend it into Chihuahua and a few even into Coahuila.

Very little information is available about the area before 1970, but there are stories of farmers in the area reporting that "hot pebbles" falling from a clear sky pelted their land. In the 1930s a pilot named Francisco Sarbia reported that his radio ceased to function when he flew over the zone.

According to Warren Smith in his book "Ancient Mysteries of the Mexican and Mayan Pyramids," the Zone of Silences was actually measured in 1969 by an engineer of the Mexican Oil Cartel named Harry de la Pena, who was prospecting in the area for possible oil-bearing geological formations. He and his group found that their walkie-talkies would not work in a triangle-shaped area measuring 3 x 3 x 3 kilometers. De la Pena speculated that large deposits of magnetic iron might be under the Zone, which would account for the poor transmission of radio waves and the sometimes reported short-circuiting of electrical equipment.

The area also has a reputation for attracting meteorites. The Museum of Mineralogy of the University of Rome has a sample of a type of meteorite known as a hexahedrite from the Bolson de Mapimi. This meteorite has been known since 1837 and it weighed at least 2064 kg.

There is also the story that in 1969, a strange meteorite referred to as the "Allende meteorite," first dodged a Russian satellite and then orbited around the Earth before crashing into the area of the Zone.

The Zone's modern notoriety can be traced to July, 1970, when the U.S. base at Green River, Utah test fired an Athena missile. The missile was supposed to land on the White Sands Proving Grounds in New Mexico, but the missile mysteriously overshot White Sands and continued south until it finally crashed into the Bolson de Mapimi. The U.S. went into the area to retrieve its missile with exaggerated secrecy precautions that served more to attract attention to the search than anything. After three weeks of searching, they found it stuck nose-first into a sand dune. They built an airstrip and a spur from the nearest railroad to the site and hauled off their property.

Supposedly, a few years later, an upper stage from one of the Saturn boosters used on the Apollo project broke up over the very same area.

Since de la Pena's visit, the Mexican government built a research facility in the Bolson de Mapimi that has become known as the "Biosphere." The facility has attracted scientists from all over the world, mainly to study the geology and flora and fauna of the area.

So, what connection does the Zone have with UFOs? Stories abound:

In October 1975, a couple named Ernesto and Josefina Diaz drove into the Zone in to collect unusual rocks and fossils. As they searched in a particularly desolate area, they noticed that a rare desert rainstorm was heading toward them. They quickly packed up and got into their new pickup truck, hoping to outrun the rain, but it was too quick for them. They soon found that their pickup had become stuck in mud and all their efforts only made it sink deeper.

Suddenly, out of the heavy rain appeared two tall men in yellow raincoats who instructed the couple to get into their pickup and drive while they pushed. In this manner, the pickup was quickly freed and rolled onto firmer ground. Diaz jumped out to thank the men, only to find that they had vanished. They could not be seen in the distance, and there was no trace of them, not even footprints.

The area is well known for "spook lights," like the "Marfa Lights" in Texas. Travelers crossing the zone, as well as locals, report seeing strange lights or fireballs maneuvering at night, changing colors, hanging motionless and then taking off at great speed. Sometimes physical traces of these nocturnal visits can be found the next day. One witness returned the next morning to the site where he had seen lights the previous night, and found that the scrub vegetation "had been set on fire." Reliable witnesses have given other, similar reports.

One story is told of two ranchers heading back from a festival who witnessed a flashing light float down from the night sky to eject human-looking occupants who glowed with the same eerie light as they walked toward them. The frightened ranchers quickly fled the area.

In 1976, a visitor to the region took the first photograph ever of a UFO landed near a place known as "Magnet Hill." The photos clearly show a shiny silver object resembling a large stewing pot. The visitor was able to take more shots of the UFO as it rose upward with a roar and disappeared to the west.

The stories of strange beings in the Zone have not depicted them as unfriendly. The staff of a small local ranch was supposedly visited regularly for a time by three tall, blond, long-haired visitors - two males and one female - who were said to be polite to a fault, very attractive and oddly dressed. Their command of Spanish was flawless and they spoke it with a musical ring.

The reason for these visits was to obtain water from the ranch's well. The odd visitors would ask their hosts to fill their canteens with water, but never requested anything else. When asked where they came from, the visitors would only smile and say "from above."

In November of 1978, journalist Luis Ramirez Reyes visited the Zone as part of a news team doing a story on the bizarre site. Foolishly attempting to find their way on their own, Ramirez and his photographer set off toward the "Biosphere" research laboratory. They soon realized that they were lost and without water or provisions. As they tried to decide what to do, Ramirez noticed three people walking towards them. He told the photographer, who was driving, to slow down so he could ask them directions. The photographer passed them by, claiming not to see anyone at all.

A few miles further on, Ramirez was amazed to see what seemed to be the same three people. This time he forced the photographer to stop the vehicle whether he saw them or not. The three were in normal clothing, but seemed ill-equipped for crossing the desert on foot. They told Ramirez that if they drove across the terrain in a certain direction, they would soon reach the Biosphere.

They did indeed reach the Biosphere by following those directions; only to meet with disbelief when they told of the three men they had met. There were no locals in the area, they were told.

Another man, Ruben Lopez, was driving through the zone one night in a van on his way to visit to a relative in Ceballos, when he noticed that his vehicle's engine had begun to sputter. All at once, he became aware of five small figures standing alongside the roadside about a hundred feet ahead. At first Lopez believed that they were children, until he noticed that they wore unusual silver one-piece outfits and that helmets resembling those used by football players covered their heads. The beings, whose adult faces Lopez could see through the open fronts of the helmets, approached van with curiosity. Lopez became terrified as they approached and began racing the van's engine in hopes of ending the sputtering. The noise startled the beings and they scattered into the desert darkness. After they were gone, the van returned to normal functioning.

The mysteriousness of the Zone has been exaggerated by some of the locals, who hope to make money selling sodas and souvenirs to those who flock to the Zone in increasing numbers. There has even been talk of building a hotel near the Zone, much to the dismay of the scientists who study the area and who fear that people looking for meteorites and UFO landing sites are disrupting the ecology of the Zone.

This article was previously published in 2003. It has been revised slightly by removing dead links and adding new ones as needed.

Print References: • "The Encyclopedia of Extraterrestrial Encounters" edited by Ronald D. Story • "The UFO Book: Encyclopedia of the Extraterrestrial" by Jerome Clark • "The UFO Enigma: A New Review of the Physical Evidence" by Peter Sturrock