Darreh Shahr County () is in Ilam province, Iran. The capital of the county is the city of Darreh Shahr. At the 2006 census, the county's population was 56,346 in 11,487 households. The following census in 2011 counted 59,551 people in 14,867 households. At the 2016 census, the county's population was 43,708 in 12,012 households, by which time Badreh District had been separated from the county to form Badreh County. Administrative divisions The population history and structural changes of Darreh Shahr County's administrative divisions over three consecutive censuses are shown in the following table. The latest census shows two districts, four rural districts, and two cities. Abdanan County and Badreh County used to be districts of Darreh Shahr County before 1995 and 2013, respectively, after which they were upgraded to county status themselves. Neighboring counties Abdanan – south Badreh – northwest Rumeshkhan County, Lorestan – north Pol-e Dokhtar County, Lorestan – east Geography Darreh Shahr county has an area of . Darreh Shahr is bounded by Kabir Kuh range to the south and Seymareh and Karkheh rivers to the north. The plains between the mountains and the rivers are fertile farmlands being cultivated for millennia. There are about of woodlands in the county, most of which are on the higher altitudes of the Kabir Kouh range to the south. The Kabir Kouh Protected Area is the most important conservation area in the county. It was established in 2001 and has an area of between the elevations of 950-2790m on the northern, greener, side of Kabir Kouh. Rivers Seymareh River Karkheh River Darreh Shahr River Sikan River Lakes Seymareh Dam Lake Climate Darreh Shahr County has a warm climate with hot dry summers and mild wet winters. July–August maximum daily temperature can as high as during heat waves, which are frequent in summer due to proximity to the Iraqi desert. Winters are generally mild but occasionally goes below freezing. The long-term average annual precipitation is at Darreh Shahr Weather Station. The lowest annual precipitation happened during the farming season of 2007–2008 with a figure as low as . The highest annual precipitation used to be in 1990–1991, after which, a deadly flood ensued. This record was broken in 2018–2019 with , which again resulted in a heavy flooding in southwestern Iran. There is almost no precipitation through the months of June to September. Darreh Shahr used to receive snow once or