It includes the montane tropical forests on the northern and northeastern slopes of the Chiapas Highlands.

The forests have a cooler climate than the adjacent lowlands, and average annual temperatures decrease with elevation.

Characteristic tree species include majagua (Trichospermum mexicanum), American sweetgum (Liquidambar styraciflua) and alder (Alnus sp).

[3] Native animals include coyote (Canis latrans) and white-tailed deer (Odocoileus virginianus), mountain trogon (Trogon mexicanus), Steller's jay (Cyanocitta stelleri), Stuart's burrowing snake (Adelphicos veraepacis), and Godman's pit viper (Bothrops godmani).

[2] Protected areas include Nahá Flora and Fauna Protection Area, Montes Azules Biosphere Reserve, and Lagunas de Montebello National Park.