In December 2005, a helicopter touched down on a boggy lakebed somewhere above 1,000 meters in the Foja Mountains of northern Papua. Eleven scientists climbed out carrying cameras, specimen jars, and the permits - six of them, painstakingly obtained - that made this one of the most legally complicated field expeditions in recent memory. They had come looking for what nobody had ever documented. Within a month they had found honeyeaters with scarlet wattles that nobody had described, twenty new frog species, a long-lost bird of paradise, and western long-beaked echidnas - one of the world's most primitive egg-laying mammals - that calmly allowed themselves to be picked up. An animal does not behave this way unless it has never encountered a predator that looks like a human. The scientists, in other words, had found somewhere people had never been.
The Foja Mountains - also written Foya, also sometimes mapped only as the eastern edge of the Gauttier Range - rise to 2,193 meters just north of the Mamberamo River basin in Indonesian Papua. Three thousand square kilometers of the interior consist of old-growth tropical rainforest. The full Foja forest tract, at 9,712 square kilometers, is the largest tropical forest without roads in the Asia-Pacific region. This is not a description that other places can borrow. The nearest villages - Sragafareh, Jomen, Beggensabah, Aer Mati, Dabra - sit far below the high forest at the foothills, and their 300 or so inhabitants hunt and gather in the lower reaches of the range. The 3,000 square kilometers of mountain jungle above them were, until 2006, a blank space that satellite imagery could map but nobody had ever walked.
The mountains had almost no recorded visitors before 1979. The reasons are structural. Much of the Foja range and the nearby Van Rees Mountains are too steep for conventional logging and too dangerous for any kind of mechanized access. There are no roads, and building one would mean engineering problems no logging company has been willing to solve. Even the Indonesian government's own permit process required the 2005 expedition - co-led by Bruce Beehler and Stephen Richards, with scientists from the Smithsonian, Conservation International, the Indonesian Institute of Sciences, Cenderawasih University, and others - to obtain six separate approvals. The only practical entry was by helicopter, and the only landing site was a muddy, seasonally flooded lakebed up in the montane forest.
What the 2005 team documented reads like a naturalist's fever dream. A new species of honeyeater, later formally described in 2007 as the wattled smoky honeyeater Melipotes carolae. Twenty previously undescribed frogs. Four new butterflies. Five new palms. A new scented white-flowered rhododendron. First-ever photographs of Berlepsch's six-wired bird of paradise and the golden-fronted bowerbird - both birds previously known only from a handful of trade skins, a few dead specimens plucked from markets decades earlier. A golden-mantled tree-kangaroo, thought to be near extinction. The echidnas that let themselves be picked up. National Geographic and BBC News sent reporters, and the Foja became briefly famous as a Lost World - the phrase stuck because it actually fit.
Scientists came back in December 2007 and found two more new species: a giant rat in the genus Mallomys weighing about 1.4 kilograms - roughly five times the mass of a common brown rat - and a pygmy possum in the genus Cercartetus, described by the researchers as one of the world's smallest marsupials. A 2008 expedition backed by the Indonesian Institute of Sciences, the National Geographic Society, and the Smithsonian added a frog with an erectile nose that inflated when the male called, a woolly rat, a rust-and-grey imperial pigeon, a 25-centimeter gecko with claws instead of toepads, and a 30-centimeter black forest wallaby in the genus Dorcopsis. Each expedition came back with creatures nobody had recorded. The forest above 1,000 meters falls within the Northern New Guinea montane rain forests ecoregion; trees of the genera Araucaria, Podocarpus, Agathis, Calophyllum, and Palaquium dominate the 1,200-meter level.
Even at elevation, the Foja range stays warm - January and July temperatures still average around 20 degrees Celsius, and relative humidity runs from 73 to 87 percent. The rainy season runs December through March, but rain can fall any month of the year. The range sees more than 2,032 millimeters of annual precipitation, enough to keep the boggy lakebed boggy. The Mamberamo-Foja Wildlife Reserve nominally protects the whole area on paper; in practice, the terrain protects it. The mountains are the buffer zone for the even harder-to-reach country further north along the Mamberamo. Whether any of this will remain intact in the face of rising resource pressure is the open question. For now, the forest is still doing what it has always done - hiding species that were never lost so much as never introduced.
The Foja Mountains center around 2.6 degrees south, 139.08 degrees east, rising to 2,193 meters in the northern interior of Indonesian Papua, just north of the Mamberamo River basin. From cruising altitude, the range reads as an unbroken dark green ridge system with almost no visible settlement, road, or cleared area - a distinctive signature of truly roadless forest. Cloud cover is frequent at the higher elevations. The nearest significant airport is Jayapura's Sentani Airport (ICAO WAJJ) well to the east; small airstrips at villages like Dabra serve the foothills via missionary and research aircraft. Expect persistent cloud build-up over the ridges; VFR navigation is difficult.