Winburndale Nature Reserve is dominated by a major ridge system running in an east and north-east direction. The ridge system is the remains of an eroded plateau, which now forms rocky slopes from the ridgetops to the watercourses and creeks.

The change in vegetation association on these portions reflects the diverse habitats over the altitudinal and geographical range. There are stands of snow gum at Mt. Horrible, while at locations slightly less exposed, snow gum-mountain gum association occurs. At lower altitudes the eucalyptus association can be mountain gum, broad and narrow leaved peppermint and Red Stringybark. On the cooler slopes, red stringybark becomes dominant. On the western slopes, scribbly gum is very common, often in conjunction with a slate strewn ground surface. The gullies, as well as containing several species of tall-growing acacias, harbour a wet sclerophyll vegetation and include such eucalypt species as rough barked manna gum, brown barrel and apple box. At the lowest altitudes red box and yellow box occur. The vulnerable capertee stringybark is found on the midslopes within the Nature Reserve.

The diverse vegetation communities provides a habitat for a number of animals, including four species of macropod, a wide range of arboreal mammals, wombats, echidnas, a variety of bird and reptile species and the Purple Copper Butterfly, one of the rarest species of butterfly in Australia. This species is endemic to NSW and depends upon blackthorn, an understorey plant species, for survival. Both quolls and Koalas have been recorded in the past.

Scientific, Recreational and educational activities are encouraged where compatible with nature conservation objectives.