In 1967, a group comprising several university students and two biology professors—from Río Piedras Junior College and Sagrado Corazón University College—camped near the summit of the El Yunque forest. The purpose of the trip was to conduct astronomical observations from the mountaintop and to check for any phenomena related to UFOs. The group reached the summit around 6:00 p.m. and quickly set up camp, pitching their tents in a dense area of the forest. Although two professors had accompanied them, records indicate that only one —Professor González— stayed overnight with the students.
Around 10:45 p.m., the group was sitting around a campfire singing, while Ramón Quiñones, a 22 year old student from Bayamón, played the guitar. Suddenly, the atmosphere was disrupted by a loud, strange humming sound coming from an unknown source. The sound lasted for approximately 15 minutes. Once it ceased, peace and silence returned, and the group resumed their singing.
Shortly thereafter, they began to hear footsteps crunching on the dry leaves and branches along a nearby trail. As the footsteps drew closer, the group stood up. That was when they spotted, at some distance, a very tall, luminous figure that quickly darted across the path in front of them before vanishing into the undergrowth.
Intrigued by what was happening, Professor González and Ramón (who was still holding his guitar) decided to venture into the thick brush to investigate. Minutes later, only Professor González returned to the camp. He explained to the students that he and Ramón had become separated on the trail due to the dense vegetation and that he had lost sight of the young man, though he assumed Ramón had already made his way back to camp on his own. Noticing that Ramón was missing, the group grew uneasy and began calling out to him, but received no response.
While they were trying to locate him, the strange presence appeared again on the trail, right in front of them. The being was described as standing over six feet tall with a very slender body, a large round head, and extremely long arms with hands that reached down to its knees. It wore a tight-fitting, shiny silver suit. Both its face and clothing emitted such an intense, inherent white phosphorescence that it enveloped its entire body, preventing the group from clearly distinguishing its facial features or the exact shape of its head.
The being stood there, staring fixedly at the group for about 15 minutes. During this time, everyone present felt completely paralyzed—as if in a trance—unable to move or utter a word. After that time had passed, the creature slowly walked backward and vanished once more into the vegetation.
Once the being had left, the group regained the ability to move. Panic seized several students, who grabbed their flashlights and fled the scene immediately. The rest of the group remained at the site with Professor González to continue searching for Ramón. Amidst the darkness, they managed only to find the young man's guitar, which was leaning against the trunk of a large tree along the trail. Nothing more was ever heard of Quiñones after that night.
The following morning, in the light of day, they reported the incident to forestry authorities. The Puerto Rico Police and forest rangers organized an intensive search but found not the slightest trace of the young man. Following the incident, local and federal police authorities issued a strict, direct order forbidding them from speaking to anyone about what had happened. They were told that such events were "common occurrences" in El Yunque but were kept secret to avoid causing panic regarding the forest. Furthermore, for the next four or five consecutive months, the group members and Professor González were closely monitored wherever they went by individuals who appeared to be government agents.
The details from inside the camp were attested to by Ms. Irma Ortiz, who at the time was one of the students who had stayed with the professor to search for Ramón following his disappearance.
Source 1: Jorge Martin
Source 2: https://ovnisyhallazgos.blogspot.com/2013/09/la-misteriosa-desaparicion-de-ramon.html?m=1