Solan District came into existence at the time of the reorganisation of the districts of the State on Ist September, 1972. The District was carved out of Solan and Arki tehsils of the then Mahasu district and tehsils of Kandaghat and Nalagarh of the then Shimla District. Administratively, the district is divided into four Sub-division viz. Solan comprising of Solan and Kasauli tehsils, Nalagarh covers the juridisdiction of Arki and Kandaghat Sub-divisions covers their respective tehsils. The total geographical area of the district according to the Surveyour General of India is 1,936 sq. km. which constitutes 3.49 percent of the total area of the State and ranks 9th amongst the district.