Ukok Plateau (Укок) is a plateau covered by grasslands located in southwestern Siberia, in the Altai Mountains region of Russia near the borders with China, Kazakhstan and Mongolia. The plateau is recognized as part of the UNESCO World Heritage Site entitled Golden Mountains of Altai as an important environmental treasure. It provides a habitat for many of the world's endangered species including one of its least studied predatory animals: the snow leopard. Other endangered species protected there include the argali mountain sheep, the steppe eagle, and the black stork. It is also one of the last remaining remnants of the mammoth steppe. There are several threats to the preservation of the Ukok Plateau, including overuse of the steppe by ranchers, a proposed road, and plans for a gas pipeline between China and Russia. The Mongolian word uheg literally means "elongated cabinet", "box", "massive mountain", or big hill with a flat top. According to the oral testimony of S. Umurzakova ukok in Kyrgyz used to refer to flat-topped mountains, i.e., plateaus. The Ukok Plateau is the high-mountainous plain located between South-Altai and Sailugem and ridges at a height of above sea level. There are 500- to 600-metre-high (1,600–2,000 ft) mountain peaks that tower above the plateau. The highest peak on the plateau is the mountain knot of Tavan-Bogdo-Ula (Five Sacred Peaks) where the highest mountain is Khüiten Peak that reaches above sea level. This is the second highest peak in Siberia after Belukha Mountain. The present-day eastern Altai-Sayan region areas of Ukok-Sailiugem could be considered the closest analogy to the ancient mammoth steppe environment. Pazyryk is the name given by modern scholars to an ancient people who lived in the Altai Mountains on this plateau who are associated with some spectacular archeological findings, including mummies found frozen in the permafrost. Many ancient Bronze Age tomb mounds have been found in the area and have been associated with the Pazyryk culture which closely resembled that of the legendary Scythian people to the west.