The Valley of Death is situated at the bottom of Kikhpinych Volcano. There is a version saying that local hunters were first to find the Valley in the early 30`s of the 20th century. The hunters` dogs got lost in the area and later their dead bodies were found in the upstream of the Geysernaya River at the bottom of Kikhpinych Volcano along with multiple corpses of other animals: gluttons, wolves, hares, etc. Although the hunters tried to leave the Valley as soon as possible, they marked a sudden deterioration of health.
Multiple expeditions stampeded into Kamchatka and tens of researchers-enthusiasts died trying to solve the mystery of the Valley of Death.
In 1975 two scientists - V. Kalyaev (zoologist) and V. Leonov (volcanist) - officially registered mass mortality of birds and animals here. In the brook with a gloomy name Noxious they noticed unusual grey-yellow boulders that looked like sleeping bears. When the scientists came closer to the boulders they found that it could hardly be a mistake: they saw bears that were not sleeping but dead. The bears` fur was covered with a small grey sulfur blush.
A research that followed the scientists` finding showed that in windless weather part of the valley was filled with a mixture of volcanic gases that consisted mainly of hydrogen sulfide and carbon dioxide. At the same time the scientists found an almost complete absence of oxygen within 1-metre height from the ground surface. That formed a kind of gas trap which killed the animals that happened to get there. In addition, only in 1982 the scientists ascertained that the volcanic gases also contained highly toxic cyanic compounds.
Staff of the Kronotsky Sanctuary regularly monitors the Valley of Death. They have already registered disappearance of nearly 25 various animal species. Amongst them are bears, foxes, hares, treecreepers, ermines, gluttons, sables, crows, partridges, and other animals.
Apart from monitoring the area the scientists also examine the brook and eliminate dead animal bodies as they attract predators and scavengers and therefore increase the chain of victims. The sanctuary staff holds all works at the Valley using the toughest measures of chemical protection.
Concentration of deadly gases, especially hydrogen sulfide, is particularly high at certain seasons. As soon as the snow melts at the Valley, a great number of mice rush there and die after inhaling the poisonous substance. Dead mice attract foxes that also die poisoned by hydrogen sulfide. The smell of dead foxes like a magnet attracts bears and gluttons ? the fate of these animals is easy to predict. However, that is not all: Steller`s sea eagles notice dead bear bodies descent to the Valley in search of food and stay there forever?
It is known that there are similar valleys on other continents but they mainly cause deaths by carbon dioxide, while ?hydrogen sulfide deaths? can be found only at Kamchatka.