Giam Siak Kecil-Bukit Batu Bioreserve is a peatland area in Riau Province of Sumatra, covering 705,271 hectares (2,723.07 sq mi) and large parts of Bengkalis Regency and Siak Regency. It is a declared UNESCO Man and the Biosphere Reserve and supports a sustainable timber industry. It is home to two wildlife reserves, namely Giam Siak Wildlife Reserve and Bukit Batu Wildlife Reserve; flagship species include the Sumatran elephant and Sumatran tiger.

Bengkalis Regency is a regency of Indonesia in Riau Province. The regency was originally established in 1956 and then included most of the northern part of the province, but on 4 October 1999 it was divided up, with most of the territory being split off to form the new Rokan Hilir Regency, Siak Regency and the city of Dumai. On 19 December 2008 a further five districts were removed to create the new Meranti Islands Regency, leaving eight districts in the Bengkalis Regency. These eight districts has increased since 2010 to eleven by the splitting of existing districts on the Sumatran mainland.