Muller mountain is a 860.00 hectares mountain range located on the border of West Kalimantana and East Kalimantan Province. Muller derives from Dutch  East Indies soldier, Major Muller.

The vegetation is of tropical rainforest and is rich of biodiversity and it is important for the sustainability of Kalimantan rivers : Barito Rivers, Kapuas River and Mahakam River.

Here are the peaks at Muller mountsins : Mt Kerihun (1790 m), Mt Mangtajung (1515 m), Puncak Liangapran (2240 m).

Birds live in Muller Mountains are ; brown magpie, golden-bellied gerygone, rhinoceros hornbill, the black hornbill, common iora, green iora, crimson sunbird, some swiftlet species, and many more birds species. They grow and live well as the good term forest condition.

Along the river grow Eugenia sp, palaquium sp and tristania obovata.

Mammals also can be found here, they are arboreal animals and spread the seeds in the forest. They can can be spotted easily as they enjoy the primary forest. Primates species in this mountain range are: Owa,  red lutung and long tailed monkey. beruk, white fronted surili, pig-tailed macaque, langur, and Sunda slow loris. Big mammals spotted in Muller Mountains are: bear, cloudy leopard, bos javanicus and badak.

It was Anton Willem Niewenhuis who named the mountain range as Muler in 1984. Georg Muller was a German soldier who later joined Dutch East Indies in the 1817. He was involved in a battle in 1818 in Sambas, inspector staff of nutmeg in Banda Neira in 1820. In 1825, Dutch delegate Muller to Kutai Kingdom that Sultan Salahuddin signed political agreement which Muller departed with 20 Javanese soldiers. The agreement was that the peace treaty required Dutch to protect Kutai and Sultan must pay 8000 Gulden. Muller and then explored the hinterland from Kutai, deeper to Kalimantan which was called as terra incognita or the unknown land. Muller lost in jungle and never came back and it is still mystery until now. (historia.id)