Usun Apau National Park: A Protected National Park in Miri Division's Geographic Landscape

Usun Apau National Park is best known for its dramatic volcanic plateau landscape and the spectacular Julan waterfall, one of Borneo's highest waterfalls at nearly 245 meters. The park protects a distinctive montane rainforest ecosystem that includes unique kerapa forest, characterized by stunted trees with gnarled trunks growing on poorly drained, nutrient-poor soils, and kerangas forest on infertile volcanic soils. The plateau serves as a critical biodiversity hotspot, supporting multiple vulnerable and near-threatened bird species including Bulwer's pheasant, the Bornean ground cuckoo, and the rhinoceros hornbill. The park's relative inaccessibility has helped preserve its natural character, making it a destination for those seeking untouched highland environments.

Usun Apau National Park was officially designated in 2005, becoming part of Sarawak's network of protected areas managed by the Sarawak Forestry Corporation. The establishment of the park provided formal protection to the Usun Apau plateau, which had previously lacked protected status despite its ecological significance. The region's volcanic history dates to ancient geological periods, with the three extinct volcanoes of Selidang, Kenawing, and Mabun serving as testament to the plateau's origins. In August 2022, Sarawak's premier announced plans to improve road access to the national park, specifically highlighting Julan Waterfall as a target for tourism development under the state's Post-COVID-19 Development Strategy extending through 2030. This development initiative represents the most recent chapter in the park's history and signals potential changes to visitor accessibility in the coming years.

The Usun Apau plateau presents a dramatic highland landscape shaped by ancient volcanic activity. The plateau covers approximately 1,550 square kilometers and averages 1,000 meters in elevation, rising prominently above the surrounding lowland terrain of central Borneo. Three extinct volcanoes mark the center of the plateau: Selidang reaches 1,370 meters, while Kenawing and Mabun both stand at approximately 1,280 meters above sea level. The plateau's edges terminate in steep escarpments that drop nearly 300 meters vertically, creating dramatic cliffs visible from the surrounding lowlands. The Julan River originates on the plateau and plummets over the edge of the northern escarpment to form the Julan waterfall, a cascading torrent of approximately 245 meters that ranks among Borneo's tallest waterfalls. Numerous streams descending from the plateau contribute to the headwaters of both the Rajang and Baram river systems, making this highland area a critical hydrological node for the entire region.

The ecological character of Usun Apau National Park is defined by its montane rainforest ecosystems, which differ substantially from the lowland rainforests that dominate much of Borneo. The plateau supports several distinct vegetation types adapted to the cooler temperatures and unique soil conditions of the highland environment. The kerapa forest represents a specialized community of stunted trees with gnarled trunks, adapted to thrive in areas of poor soil drainage and low nutrient availability. The kerangas forest occupies areas with more fertile volcanic soils, featuring taller trees with relatively thin trunks that have developed on the nutrient-rich substrates resulting from ancient volcanic activity. The lower slopes of the plateau support hill dipterocarp forest, connecting the montane environment to the broader lowland rainforest ecosystem. This mosaic of habitat types creates ecological diversity within a relatively compact area, supporting both species adapted to highland conditions and those that range across elevation gradients.

Usun Apau National Park supports a notable collection of bird species, several of which carry conservation designations due to their limited distributions or declining populations. The plateau has been recognized as an Important Bird Area, highlighting its significance for avian conservation in Borneo. Among the vulnerable species found here is Bulwer's pheasant, a distinctive ground-dwelling bird with striking plumage. The Bornean ground cuckoo represents another rare sighting for patient observers. The rhinoceros hornbill, with its impressivecasqued beak, frequents the forest canopy. Other notable species include the ferruginous partridge, the Dulit frogmouth and Gould's frogmouth (both nightjars with cryptic camouflage), Whitehead's trogon, Hose's broadbill, the black oriole, the Sunda laughingthrush, and Everett's thrush. Beyond birds, the park harbors the gracile slender toad, a species known only from the Usun Apau plateau and one additional locality, making it particularly significant for amphibian conservation.

The designation of Usun Apau as a national park in 2005 provided formal protection for a volcanic plateau ecosystem that had previously lacked dedicated conservation status. The park's recognition as an Important Bird Area underscores its international significance for biodiversity conservation, particularly for the collection of vulnerable and near-threatened species that depend on montane rainforest habitats. The isolated nature of the plateau has historically limited human impact, preserving ecological integrity despite surrounding lowland deforestation. The park's role as a watershed for the Rajang and Baram rivers extends its conservation importance beyond its borders, as these river systems support downstream ecosystems and communities. Management by the Sarawak Forestry Corporation provides institutional capacity for protection and monitoring, though the park's remote location presents challenges for enforcement and visitor management.

Usun Apau National Park is situated within the traditional lands of indigenous communities in central Sarawak. The highland plateau and its resources have long been part of the cultural landscape for local Dayak peoples, who have maintained connections to these lands through traditional land use and resource management practices. The park's relative inaccessibility has limited widespread human settlement on the plateau itself, preserving both ecological values and cultural associations with the landscape. While the park does not contain extensively documented archaeological sites or monuments, the natural features of Usun Apau—including the waterfalls and volcanic formations—hold cultural significance for local communities. The announcement of improved access roads in 2022 represents a new phase in the park's relationship with surrounding communities and may bring both tourism opportunities and management challenges.

The Julan waterfall, dropping approximately 245 meters in a single cascade, stands as the park's most spectacular natural feature and ranks among Borneo's highest waterfalls. The volcanic plateau landscape, with its three extinct volcanoes and dramatic 300-meter escarpments, offers trekking opportunities through terrain unlike the more common lowland rainforests of the region. The montane forest ecosystems, including the distinctive kerapa and kerangas forests, provide habitat for species found nowhere else on Earth. The relative remoteness of Usun Apau, while a barrier to casual tourism, has preserved a sense of wilderness that distinguishes it from more accessible protected areas.

The best time to visit Usun Apau National Park aligns with the broader dry season in Sarawak, typically from March through October, when rainfall is reduced and trail conditions are more favorable for trekking. The montane environment experiences cooler temperatures than the surrounding lowlands, providing a more comfortable climate for physical activity. However, visitors should be prepared for weather variability even during optimal seasons, as mountain environments can generate fog, mist, and afternoon showers regardless of the period. The wet season from November through February brings higher precipitation, which can make trails more challenging and access roads more difficult to navigate. Given the park's limited infrastructure and remote location, visitors should plan ahead and be prepared for basic facilities upon arrival.