Kulik then tried to make headway through the untamed Siberian forests, or taiga as the Russians call it, but was forced to turn back after heavy snowdrifts almost froze the horses to death. For three days Kulik was forced to remain in the snow-bound village of Vanavara, but during this period he interviewed many of the Evenki hunters who had witnessed the Siberian fireball's arrival on this planet.

The tales of the sky being ripped open by a falling sun and of a great thunder shaking the ground made Kulik even more eager to penetrate the taiga to find his holy grail. When the weather gradually improved, Kulik set out for the Tunguska Valley. When he finally reached the site of the mysterious explosion, he was almost speechless. From a ridge overlooking the scene, Kulik took out his notebook and scribbled down his first impressions of the damage wreaked by the cosmic vandal. Kulik wrote:

From our observation point no sign of forest can be seen, for everything has been devastated and burned, and around the edge of the dead area, the young, twenty-year-old forest growth has moved forward furiously, seeking sunshine and life. One has an uncanny feeling when one sees twenty to thirty-inch giant trees snapped across like twigs, and their tops hurled many yards away.

Kulik then proceeded towards the felled forest, but two of the guides who had taken him and his assistants to the area refused to go any further. The guides told the bemused scientist that there was something or someone still lurking about in the area. Kulik thought the guides were superstitious fools, but they told him that strange things had been seen at twilight in the shadows of the dead taiga.

The guides returned home and Kulik fortunately met a few bold members of the Evenki tribe, who took him and the researchers further into the taiga. By June, Kulik and his men had reached the middle of the explosion site, where uprooted trees were scattered from the centre of the blast like the tangled spokes of a wheel. There were no signs of a crater.

Kulik realised that the explosion had occurred above ground. The Evenki tribesmen seemed to become very uneasy in the middle of the devastation zone, and started to talk about a supernatural presence in the area. But Kulik didn't have time to listen to such irrartional ramblings of the nomads; he had limited time to collect data for his friends back home at the Russian Academy of Sciences. There were three further expeditions to the site of the Tunguska explosion, all of them headed by Kulik. In 1941, Hitler attacked Russia. The 58-year-old Leonid Kulik volunteered to defend Moscow, but was wounded by the Nazis. He was captured by German troops and thrown in a prison camp where he died from his wounds.

The next three expeditions to the Tunguska Valley in 1958, 1961 and 1962 were led by the Soviet geochemist Kirill Florensky, who used a helicopter to survey and chart the blast area. Florensky's team sifted the soil in the area and discovered a narrow strip of dust which was of extraterrestrial origin. The dust consisted of magnetic iron oxide (magnetite) and minute glassy droplets of heat-fused rock. Florensky carefully checked the radiation levels at the site, but the only radioactivity present seemed to be from the fallout which had drifted into the area from distant Soviet H-bomb tests.