The forests of Overa and Aru were initially declared as ‘Reserves’ vide Cabinet Order No. 710‑C of 1945(G) Dated 17.07.1945. Later keeping in view its rich potential for wildlife it was upgraded as ‘Man and Biosphere Reserve’ vide Govt. Order No. FST‑20 of 1981 Dated 04.02.1981. The area was finally declared a ‘Wildlife Sanctuary’ vide Govt. SRO No. 154 Dated 08.03.1987 issued under Endorsement No. FST/WL/SAN/Overa/97 Dated 18.03.1987.