Peppara Wildlife Sanctuary consists of Part of Palode reserve (24sq.kms) and part of Kottoor reserve (29sq.kms). The total area of the sanctuary is 53 sq.kms. The total water spread of the reservoir is 5.82 sq.kms.

The sanctuary is located about 50kms. north east of Thiruvananthapuram city in Nedumangad taluk of Thiruvananthapuram district between longitude 76°40' and 77°17' east and latitude 80°7'and 8°53' north. General topography of the area is hilly with elevation varying from 100 m to 1717m. Rainfall and other climate factors are similar to that of Neyyar Wildlife Sanctuary. There are 13 tribal settlements in the sanctuary. Eleven are in Athirumala section and two are in Thodayar section.

The Following major forest types are recognised in the peppara wildlife sanctuary.

1 .Southern hilltop tropical evergreen
This type of forest is of stunted evergreen, found above 1000m elevation on the top of hills. They are exposed to heavy wind and less favourable soil and climatic conditions.

2 .West coast semi- evergreen
A transitional zone between evergreen and moist deciduous, this type occurs mostly in hill slopes from 150 to 1050m. The riparian areas also contain them.

3. Southern moist mixed deciduous forests
This type of forest covers more than 60% of the tract along the lower slopes of hills.

The major mammals include elephant, gaur,sambar, barking deer, mouse deer, wild boar, tiger, panther, wild dog, lion tailed macaque, Nilgiri langur, Malabar squirrel etc. Water birds like darter, little cormorant, pied king fisher and egrets are also common. Many kinds of snakes including the king cobra and python are also present in this sanctuary. The area has a variety of moth and butterflies.