Cholistan Desert (Urdu: صحرائے چولستان, also locally known as Rohi) sprawls thirty kilometers from Bahawalpur, Punjab, Pakistan and covers an area of 16,000 km². It adjoins the Thar desert extending over to Sindh and into India.The word Cholistan is derived from Cholna which means "moving". The people of Cholistan lead a semi-nomadic life, moving from one place to another in search of water and fodder for their animals. The dry bed of the Hakra River runs through the area, along which many settlements of the Indus Valley Civilisation have been found.Nearly 300 Harappan sites (cf. Indus Valley Civilisation) have been found in the Hakra valley [1], mostly by M. R. Mughal, which account for 20% of all Harappan sites now . Cholistan has changed amazingly over the history. The desert was under perennial regular irrigated cultivation till 1200 BCE and under seasonal regular irrigated cultivation till about 600 BCE[citations needed]. The area turned into arid and desolate desert with drying up of River Hakra. These days again, the desert is undergoing a process of profound change because of canal system originating from the River Sutlaj. But one can still find people living in houses made of mud and straw almost as they might have been living 200 years ago