Conservation planners in the early 2000s described the area in bloodless terms: a former Khmer Rouge stronghold containing settlements of Indigenous people and former Khmer Rouge families. Behind that phrasing sit two very different histories sharing the same watershed. Indigenous communities had been living in and from these valleys long before any political movement claimed them, gathering resin, honey and rattan on a seasonal round. The other households were the remnants of a collapsed insurgency - families with children, growing rice on burnt clearings, with nowhere obvious to go once the movement they had belonged to dissolved around them. Both groups used the forest because using the forest was how you ate. Sanctuary boundaries had been drawn on maps in Phnom Penh, but through the early 2000s hardly anyone in these hills knew the designations existed, and the country's protected estate here was too large and too rugged for anyone to monitor.

The protected forest was established in 1999 under the Forestry Administration, and for the next decade and a half the range was governed by an awkward split. Conservation International backed a Central Cardamom Protected Forest project with the Forestry Administration from 2001 to 2004. Separately, Fauna & Flora International worked from 2003 to 2007 with the Ministry of Environment on the neighbouring Phnom Samkos and Phnom Aural wildlife sanctuaries - management planning, ranger capacity, community engagement, awareness-raising and the unglamorous work of building financing that would outlast the grant. Two sub-projects, two ministries, two start dates, one continuous forest that recognised none of it. That ended in 2016, when the Ministry of Environment assumed responsibility for the area and the protected forest was reconstituted as a national park under a government sub-decree. The paperwork was late. The forest, remarkably, was still there.

The park is home to more than 400 vertebrate species, roughly 70 kinds of fish and over 200 documented plants, some found nowhere else. Asian elephants move through it. So do sun bears and Asiatic black bears, clouded leopards, dholes, leopard cats, and pileated gibbons whose whooping duets carry further at dawn than any other sound in these hills. Just to the northeast, inside the adjoining Phnom Aural Wildlife Sanctuary, Phnom Aural rises to 1,813 metres - the highest point in Cambodia. What sustains all of it is water. Koh Kong province, which holds part of the park, sits under a tropical monsoon that runs from roughly April to October and peaks between June and September; the weather station at Koh Kong averaged about 3,633 millimetres of rain a year between 2000 and 2005. Daytime highs hold at 30 to 34 degrees Celsius, nights at 22 to 25. Nothing here ever really dries out.

The threat that keeps rangers walking is not the chainsaw but the snare. A loop of bicycle brake cable costs almost nothing, catches whatever steps into it, and kills indiscriminately - gibbon, muntjac, bear cub, elephant calf. Patrols through the park in 2022 documented illegal land encroachment and illegal logging, and confiscated and destroyed traps, snares and other equipment. Measured against the rest of the region, the results are hard to argue with: the park lost only around 1.2 percent of its forest cover between 2000 and 2015, in a corner of the world where neighbouring landscapes were losing that much in a year. The pressure has not gone anywhere. It simply meets, now, a few hundred people willing to spend the wet season walking uphill through leeches to find wire loops before the animals do.