Classic cases · Puerto Rico · Classic case

53 years ago: creatures in the El Yunque rainforest

7 min read

On the night of October 20, 1973, nine people climbed one of the peaks of Puerto Rico's rainforest to see UFOs. By morning they were telling of unknown figures, giant footprints leading to the parking lot, and later of a haunting at home. It is one of the strangest cases of the great 1973 UFO wave, and it shows well how a story grows as it is retold.

When: October 20, 1973
Where: El Yunque mountain, Puerto Rico

In northeastern Puerto Rico, on the slopes of the Luquillo Mountains, lies El Yunque, the only tropical rainforest in the United States National Forest System. The Taíno people revered it as the home of one of their gods, but by the 1970s it had gained a very different reputation: stories of disappearances, strange lights and unknown creatures became attached to it.

1973 was one of the busiest years in UFO research. Researchers of the time called it the "Year of the Humanoid," because a great many close encounters of the third kind were reported worldwide. The famous Pascagoula case in Mississippi happened in the same month, on October 11, and the wave reached Puerto Rico as well. It was in this atmosphere that a small group set out for the summit of El Yunque.

The excursion

The case was first documented by Puerto Rican researcher Noel E. Rigau. His account was published in Summer 1974 in the journal Awareness, and it is based on an interview conducted on November 9, 1973 with one of the participants, Efraín Arroyo.

On Saturday, October 20, at around 6 p.m., nine people arrived at the trail leading to the summit:

Heriberto Ramos, an engineer,
Juan Jiménez, a commercial pilot, and his brother, Luis Jiménez,
Efraín Arroyo, a university student,
and a high school teacher with four of his students, who did not want their names made public.

They had come specifically to observe UFOs: they brought a camera loaded with infrared film, flashlights, signaling devices and camping gear.

Something strange happened on the way up. Three young women and a young man were coming down toward them with a single flashlight. One of them asked which way the main road was. The group found this odd, since it was already getting dark and no one else's car was in the parking lot besides theirs. According to the witnesses, the three women looked strikingly alike and were dressed identically: blue trousers and red sweaters.

Midnight on the mountain

Around midnight, one of the participants said he felt as though someone was watching them. Shortly afterward they heard a noise. In near-total darkness, Juan Jiménez took photographs with the infrared film in the direction of the sound. When they went over with a flashlight, they found deep footprints in the flattened grass, with broken branches next to them.

Ramos and Arroyo then split off from the group. By the light of the moon occasionally emerging from the clouds, they glimpsed four figures coming down a narrow path. At first they could only see shadows moving in a zigzag. The figure in the lead was holding a small device with flashing green, blue and red points of light, and was moving it up and down. When a companion coming up behind them shone a light on one of the creatures, they immediately moved away. According to the witnesses, at that moment they were overcome by an unusual calm they had never felt before. They tried several times to get closer, but each time the creatures withdrew.

According to the witnesses' description:

the minimum distance was 4.5–6 meters;
the creatures were 1.5–1.8 meters tall, with long arms; they did not see their hands but sensed that they were large;
in the flashlight beam they saw large eyes, a nose and pointed ears, and some also saw horns, though not everyone agreed on this;
they moved quickly, almost in leaps, as if swinging from one side of the path to the other by grabbing onto branches.

The tracks

The group kept watch all night and started down at 5:30 a.m. Along the entire length of the trail, all the way to the parking lot, they found footprints much larger than a human's, along with smaller, different tracks. The branches of the bushes were broken, some torn off completely. According to the witnesses, the depth of the tracks suggested great weight; their own shoe heels barely left a mark on the same ground.

What followed at home

On October 21, Juan Jiménez's mother was sitting on the balcony of the house with a neighbor when both heard a noise from inside the house, as if someone were tampering with the film brought home or pulling out the reel. They were so frightened that they fled and only returned hours later with the rest of the family.

The next day Efraín Arroyo took the film to be developed, and that night his parents also reported strange phenomena. The floorboards seemed to move on their own, dull thuds were heard from the roof, something like a bell sounded, and an electric fan rolled across the floor by itself. The noises stopped after a few days. Rigau himself was inclined to regard them as poltergeist phenomena.

The developed infrared film showed nothing significant, and it was thrown away shortly afterward. Several participants were plagued by nightmares. One of the anonymous students claimed that a creature appeared to him and told him that he would forget everything.

How did the story live on?

We are not aware of any official investigation or statement by authorities: the case was dealt with only by the press and civilian UFO researchers. The U.S. Air Force's UFO program, Project Blue Book, had already been closed for four years at that point.

After a thorough investigation, the case received wide press coverage, mainly because the witnesses were serious people held in high regard in their communities. Over the decades, however, several versions have emerged, and they do not always agree.

In UFO researcher Scott Corrales's account, the number of creatures is already five or six, they have claw-like hands and elongated ears, and they surrounded the campers. In this version Ramos stood less than three meters from one of the creatures, described a triangular head and extraordinary eyes, and even touched the creature, which did not move at all. Rigau's original account says nothing of this: there, even the minimum distance was 4.5 meters, and the creatures moved away at every approach.

Albert Rosales's humanoid catalog, citing David Webb's 1976 book 1973 – Year of the Humanoid, also publishes an alleged eyewitness sketch, as well as a similar sighting by another group of campers on the same day, earlier, in the afternoon.

The 1973 El Yunque stories have often been mixed up with one another online ever since. Researcher Gary Reddin, for example, showed that the Rosales sketch is regularly attached to another case that cannot be verified by sources, the so-called El Verde creature.

The sober take

One of the most important lessons of the case is how the story "grew" over time: four creatures became five or six, and a figure seen from a distance became a creature that was touched. The earliest and most detailed source, Rigau's 1974 account, is the most restrained, and this makes the Credibility of the later additions questionable.

Several prosaic factors may have played a role. The group went up specifically to see UFOs, in the middle of the great 1973 wave. The rainforest at night, the moon emerging from behind the clouds, the flicker of flashlights and fatigue create ideal conditions for interpreting vague figures and noises as the expected experience. The strange group heading down suggests that others were also on the mountain that night, so human pranks or other hikers could also explain some scenes, such as the flashing device. No large wild animals live in the forest (the largest mammals are rats, bats and mongooses), but feral dogs do occur. On a muddy tropical trail, footprints easily smear and stretch, and the group itself walked back and forth during the night. The infrared film recorded nothing. And the noises at home and the nightmares may be well-known psychological aftereffects of a frightening experience.

None of this refutes that the witnesses truly went through a deeply unsettling experience. However, no physical evidence has survived, and the story visibly changed as it was retold.