Located at the upstream of Kapuas river, on the boundary of Sarawak (Malaysia) and Indonesia. This area is very important for the watershed of Kapuas, Rajang and Mahakam Rivers. Dayak ethnic used this area for subsistence need. The highest point is Gunung Lawit (1767 m).
It is predicted that this area has the same bird composition with G. Batu Liang or Hose mountains in Sarawak. The prediction is confirmed by Raharjaningtrah & Prayogo (1997), although some of species need to be re-assesed, such as : Wallace's Hawk-eagle Spizaetus nanus, Blue-wattled Bulbul Pycnonotus nieuwenhuisii, Hook-billed Bulbul Setornis ciringer, Black-browed Babbler Malacocincla perspicillata, Eye-browed Jungle-flycatcher Rhinomyias gularis.