 The park is an eastward extension of the Western Ghats hills formed by separation of the India-Madagascar-Seychelles blocks of East Gondwana in the Early Cretaceous period about 120 million years ago.It is surrounded to the north, east and south by the Deccan Plateau formed later in the massive Deccan Traps eruption 66 million years ago as India drifted over the Reunion Hotspot.The Palani hills are most prominent towards the west, ranging from to (5,906 ft - 8,376 ft).