Kyok-Tash Cave

Kyok-Tash Cave (also known as Ekologicheskaya, or Evening Promenade) lies in the Altai Republic, in the northern part of Shebalinsky District, on the Kamyshla karst plateau between the Kamyshla and Ustyuba rivers. The nearest landmark is the village of Kamlak on the Chuysky Trakt highway, about 17 km from the entrance along an old track running up a ravine. The name means "blue stone" in the Altai language: the local Cambrian limestone has a bluish tint, most visible on a wet, polished surface of the rock.

Geology and depth

The cave is formed in Cambrian limestone and crystalline schist that make up the ancient core of the Katun anticlinorium. Kyok-Tash reaches a depth of 350 meters (321 meters by other estimates), with 2,100–2,300 meters of passages. This makes it the deepest cave in Siberia and the deepest in Russia among caves formed in Paleozoic rock. The entrance is a narrow slit about half a meter wide between limestone blocks at the bottom of a ravine, easy to miss among the boulders where two gullies meet.

History of exploration

The first information about the karst near the village of Kamyshla dates to the mid-1960s. In 1977 a Novosibirsk caving team led by Valentin Mishin descended the 25-meter entrance shaft. The main part of the cave was opened in 1983 by Barnaul cavers led by Valery Polunin, who reached the Khaos chamber at a depth of 220 meters; around that time the cave also acquired the name Ekologicheskaya. In 1984 a Novosibirsk team led by Stanislav Domogashev reached the bottom at 350 meters. In 1990 two Novosibirsk cavers passed the sump at the end of the "Barnaul bobsled" passage without scuba gear, holding their breath. Exploration continued later: in 2016 a new passage system called Sevastopolskaya, about 600 meters long, was discovered, and biospeleologist Ilya Turbanov described several small crustacean and insect species new to science inside the cave. Since 1996 cavers from Barnaul, Novosibirsk, Biysk and Gorno-Altaysk have kept studying the cave.

Inside the cave

Down to about 200 meters the cave is a sequence of shafts linked by short meanders: the first and second shafts, both 20 meters deep, are usually dry and fixed with bolts, and the fourth shaft, 25 meters deep, leads to the fifth near the Mrachny ("Gloomy") chamber — the largest in the cave, over 200 square meters in area and 25 to 35 meters high. Further on lies the deepest shaft in the cave, Neti, 60 meters deep, named after the Novosibirsk institute where its first explorers studied. Below, at around 200 meters, a fault zone holds large chambers and a system of old dead-end passages, and a narrow, tall meander with small lakes is known as Morskoy Prospekt ("Sea Avenue"). The old bottom of the cave lies at minus 340 meters, and a newer sump has been found nearby at minus 312 meters. During rain or snowmelt the cave floods heavily and becomes impossible to enter.

Status and visiting

Since February 16, 1996, Kyok-Tash has been a regional geological nature monument of the Altai Republic, protected by the Altai Experimental Farm. The protected area covers 1 hectare. A full traverse of the cave is rated grade 3B in caving difficulty and requires special equipment and rope skills: it is a destination for trained cavers, not a casual walk.

Getting there

The route starts from the village of Kamlak on the Chuysky Trakt highway. From the bridge over the Kamlak stream, the track climbs up the ravine onto the plateau; the total distance to the cave is about 17–18 km on foot or on horseback. The entrance lies on the plateau, where two ravines meet, on the side of the basin opposite the trail.