According to an anecdote, two hunters found Death Valley in the 1930s. When they set foot in this land, they found the place extremely dry, without any plants and animals living. They only see many dead animals.

After a few minutes, the two people felt a headache and left the Death Valley. This decision helped them keep their lives. This is because in the 1940s and 1950s, many people went to Death Valley to decipher the mysteries in this place, but they did not return.

According to the local people, about 80 people came to Death Valley to disappear and mysteriously never come back.

On July 28, 1975, a group of researchers led by Vladimir Leonov headed to Death Valley to mystify and witness animal dead lying on the wasteland.

In the face of this strange phenomenon, from 1975 - 1983, scientists conducted research to decipher the cause of the death of the ill-fated animals in Death Valley.

After a period of research, experts discovered that many animals, including Death Valley birds lost their lives, were caused by a series of toxic gases released from the activity of nearby volcanoes.

In particular, experts found a mixture of toxic gases: Hydrogen sulfide (H2S), Carbon dioxide (CO2), Sulfur dioxide (SO2), Carbon disulfide (CS2) and some other toxic gases.

These toxic gases accumulate in lowland, windy areas in the valley. Any animal that inhales these dangerous gases for a certain period of time will lose their life.

Stranger and more frightening, the dead bodies of Death Valley are largely unresponsive thanks to the toxic gases preserved from the bacteria that break down the dead bodies.