Rise high enough above the savanna of southern South Sudan and the world changes. The grass and thornscrub fall away, and crystalline rock heaves upward into the Imatong Mountains, green with forest, cool with rain, crowned by Mount Kinyeti at 3,187 metres, the highest point in the country. These peaks are an island. For thousands of years dense montane forest here stayed cut off from other forests by a sea of dry savanna, and in that isolation life went its own way. The Imatongs hold hundreds of plant species found nowhere else in South Sudan, and animals that have drifted, over the ages, into forms slightly their own. It is a place of rare biological wealth, and of recent, brutal history.
The mountains sit at a crossroads of three botanical worlds, the West African rainforest, the Ethiopian highlands, and the East African ranges, and they have borrowed from all of them. Climb through the zones and the forest changes with the altitude. Lowland woodland of Albizia and Terminalia gives way above 1,000 metres to montane forest of Podocarpus and Croton, and higher still, near the summits, the trees thin into Hagenia woodland, heather thicket, and bamboo. Around 1,500 millimetres of rain falls each year. Because these forests were marooned by savanna since the last great wet period some twelve thousand years ago, the mammals here show their deepest differences from their lowland cousins, evolution quietly at work on an island made of altitude rather than water.
A 1984 survey found the slopes alive: colobus and blue monkeys in the canopy, bush-pig in the undergrowth, a bushbuck subspecies unique to the range. In the least-disturbed uplands to the south-east, the ones hunters reached last, elephant, buffalo, leopard, hyena, and duiker still moved through the trees. The birds are the real treasure. The Imatong forests shelter species found in no other part of South Sudan and serve as a way-station for European songbirds migrating to winter in East Africa. Among the rarest is the endangered spotted ground-thrush, a secretive forest bird whose presence marks the Imatongs as a place of genuine ornithological importance, a refuge that BirdLife recognises as significant on a continent that is losing such places fast.
Remoteness that protected the wildlife also drew war. During the Second Sudanese Civil War, the Imatong Mountains became a haven for the Lord's Resistance Army, the brutal rebel force that, from 1986, raided and looted villages along the Sudan-Uganda border. South Sudan's own rebel army, the SPLA, joined Ugandan forces against them, and the struggle ground on for more than two decades. In late April 2002 the LRA massacred more than four hundred people in the Imatong area, with the town of Katire bearing the worst of it. The militia did not finally leave the region until April 2007. The scars are everywhere in how people live: by one 2010 account, nearly every adult man in nearby Ikotos owned a gun, some households eight or nine, and violence had become an ordinary fact of life.
The Imatongs are also a slow-motion lesson in loss. From the 1940s the British colonial administration cleared native forest in the Kinyeti basin to plant fast-growing softwoods for timber, and the project pulled labourers into the hills who began farming the slopes. A 1952 forest reserve was meant to protect the high ground, but during the civil wars no one enforced it. Driven by need, people pushed their fields ever higher, up to 2,300 metres, onto slopes too steep to hold soil, and the rivers ran muddy with the result. By 1984 only the steepest faces and the inaccessible south-east still held natural forest. Since 2009 conservationists have used satellite imagery to track the shrinking canopy and have proposed turning part of the reserve into a national park, an attempt to save what an island this rare still has left.
The Imatong Mountains rise in Eastern Equatoria, southeastern South Sudan, near 4.1°N, 32.85°E, extending south into northern Uganda. The massif climbs sharply from plains that fall from about 1,000 metres at the border to 600 metres at Torit in the north; Mount Kinyeti, the high point at 3,187 metres, anchors the central block near the Ugandan frontier. The range is an unmistakable green, forested upland set against dry savanna, roughly 190 km southeast of Juba. Nearest major airport is Juba International (HSSJ) to the northwest. Treat these as serious mountains: expect orographic cloud, rapid weather changes, rain on the windward slopes, and afternoon storms. Maintain safe terrain clearance over the high central peaks.