The Kopet Dag is a mountain range along the southern border of Turkmenistan with Iran. Highest peak in Turkmenistan is Mount Rizeh (2912 m). It is an area of dry foothills and sandy slopes culminating in mountain plateaus with steep ravines. In the western part of the range in Turkmenistan are Karakala Nature Reserve, abode of the Iranian leopard, and the interesting region of Nokhur where Turkmen tribes inhabit the valleys of the river Sumbar.