Most of the province is covered by hilly landscape. In the north is the Lam Pao dam built 1963-68, storing 1,430 million m of water for flood prevention and agriculture. The Lam Pao reservoir effectively cuts the northern part of the province in half but there are car ferries connecting the district of Sahatsakhan in the east with the district Nong Kung Si in the west, saving up to one hour off the journey by road. On the northwestern creek of the reservoir a road bridge now connects the village of Ban Dong Bang in the west with the district town of Wang Sam Mo in the east. Although the bridge was constructed several years ago (pre 2000) it is not featured (2006) on any commercially available road maps. Making the border with Sakhon Nakhon Province is the Phu Phan mountain range, which is preserved as a national park.