When nearby Cameron Highlands was developed, many of the 6000 indigenous people living there were driven out to less hospitable areas on the edge of cliffs as choice land became scarce. NGOs say building the highland road would simply push people who depend on the forest further into the jungle. Another concern is the country's water supply. A number of important rivers flow from the Main Range, and disturbing them could create water shortages downstream. The Main Range is by far the main water catchment area for peninsular Malaysia.
Erosion is a threat because the terrain is steep and rainfall heavy.
The mountain slope has a 27-degree angle which rises in places to 54 degrees. Other developments nearby have already turned to tragedy. In 1994, a 96-unit apartment built on a slope collapsed because of a landslide. By denuding the slopes of trees, hillsides lose the precious vegetation they need to retain soil and keep it from sliding down the mountainside. With 3000 mm of rain falling on the highlands each year, the slopes are waterlogged and ready to slip at a moment's notice.