The boundary commence from the point where the Kannan Devan Hills Produce Village boundary meets the Inter State boundary between Kerala and Tamil Nadu at point 5540’ (1689m). From that point, the boundary runs along the Inter State boundary passing through peaks with altitude of 3984′ (1214 m), 5011′ (1527 m), 5885′ (1794 m) and 7388′ (2252 m) to Perattumala 7033′ (2144 m). Thence turning southeast, the boundary reaches Kumarikkalmala 8275′ (2522 m).
The boundary follows the Kannan Devan Hill Produce Village boundary along the ridge through Kattumala 8373’ (2552m) and then to Perumalmala 7736′ (2355 m) till it reaches Tirumudi 5676′ (1830 m).
The boundary follows the western boundary of Chattamunnar Estate (Thalayar group), northern boundaries of Vaguvarai and Nayamakkadu estate to meet the Kannan Devan Hill Produce Village boundary about 3 Km south west of Rajamala peak 7209′ (2197 m).
The boundary follows the Kannan Devan Hill Produce Village boundary to Rajamala 7209’ (2197 m) and then turning northeast, the boundary reaches Sambamala 7581′ (2311 m) and thence to Bhimamala 4719′ (1438 m) and from there turns in a north east direction to Kolukkumala, 7137′ (2175 m) and thence proceeds in north direction to the starting point at 5540′ (1689 m) passing through Erumamala, 7496′ (2284 m) and Erumapettimala, 6999′ (2133 m). The boundary notification is vague at some points where the distinction between National Park and tea estates is not clear enough.
The southern boundary with the tea estates still remains vague at few points. For the rest of the park, the boundaries are clear and demarcated. On the south boundary between Lakkomkudy and Chattamunnar, a small area (about 5 ha) has been under occupation. There is no reliable record regarding the time of occupation.
The boundary of the Lakkom Muthuvan settlement situated inside the park on the southern periphery is demarcated with ‘kayyala’. The individual right over land is already settled as per Forest Rights Act. The park is under a single Forest Station with headquarters at Lakkom and there is no internal demarcation.
The notification follows the ridges as the boundary and the ecological boundaries of the park extend into the Anamalai Tiger Reserve in Tamil Nadu, Chinnar Wildlife Sanctuary under Munnar Wildlife Division and Koodakkad proposed reserve under Marayoor Division in the north, Koodakkad proposed reserves under Marayoor Division in the east, the Grasslands of KDHP company, Mankulam Division and Munnar Division in south and Anamudi Reserved Forest under Munnar Division in the west. These areas are vital as fawning and escape cover for a species like the Nilgiri Tahr.