[4] The watershed covers 2,975 ha and is divided among four barangays: Libmanan's Duang Niog and Tanag, and Pasacao's Bagong Silang and Salvacion.

Caranan and Itulan rivers sources, as well as a lakelet named Caliryuhan, may be found in Barangay Bagong Silang's forest area.

Tanag has Asupre Creek, Duang Niog has four springs on private land, and two streams in Sitio Mensuro, which is along the Malansad River's route.

[5][6] Sightings of several bird species, majority of which are endemic to the Philippines and northern Luzon, have been recorded on the mountain, this includes rufous coucal (Centropus unirufus), Philippine trogon (Harpactes ardens), coppersmith barbet (Psilopogon haemacephalus), Philippine hanging parrot (Loriculus philippensis), yellow-bellied whistler (Pachycephala philippinensis), blue-headed fantail (Rhipidura cyaniceps), black-naped monarch (Hypothymis azurea), yellow-wattled bulbul (Poliolophus urostictus), white-browed shama (Copsychus luzoniensis), bicolored flowerpecker (Dicaeum bicolor), grey-throated sunbird (Anthreptes griseigularis), and flaming sunbird (Aethopyga flagrans).

The ants are thought to have lived in the Kalupnitan Caves (now Colapnitan) on this mountain, where Handyong drove and buried alive the crafty, sweet-voiced serpents who pretended to be charming maidens.

On March 8, 1965, a Filipinas Orient Airways Douglas DC-3A crashed and burned in the slope of Mount Bernacci, as it was approaching Naga Airport.