The Tenasserim Hills are part of a long
granite mountain ridge that is older than the
Himalayas. Further south from the 16th parallel, the
Shan Hills break up into narrow steep-sided ranges, the Dawna Range in the west and, parallel to it at the southern end, the peninsular Tenasserim Mountains that extend southwards along the Kra Isthmus. Eastwards, in
Kanchanaburi province on the Thai side, the mountain range is crossed by the
Khwae Yai River and the
Khwae Noi River. In this area small hill ridges alternate with narrow valleys that are often only about 2 km wide and further east there are only isolated hills, where the range ends in the Central Plain of Thailand. Further south the
Phachi, the
Pran Buri and the
Phetchaburi River flow eastwards from the range towards the
Gulf of Thailand. The westernmost range is separated from the Tenasserim coast by the
Three Pagodas Fault. West of it lie the Dawna Range, the
Karen Hills and the valleys of the
Salween and the
Gyaing. Southwards on the western side, the
Ye,
Heinze,
Dawei (Tavoy),
Great Tenasserim (Tanintharyi) and the
Lenya rivers are relatively short and flow into the
Andaman Sea. Further south the
Kraburi River forms the southern border between Thailand and Burma.
Sections •
Northern: The northern end of the range overlaps with the
Dawna Range and is not clearly defined. Some geographic works set the
Three Pagodas Pass as the northern limit. The
Tenghyo Range is a small northern prolongation following the
Andaman Sea coast. The highest points in the northern section of the range are in the
Bilauktaung subrange in Myanmar, where 2,072 m high
Myinmoletkat Taung is the highest point of the northern section of the Tenasserim range, and with a prominence of 1,857 m one of the
ultra-prominent peaks of Southeast Asia as well. Other noteworthy peaks are Ngayannik Yuak Taung 1,531 m and Palan Taung 1,455 m. The average elevations of the Tenasserim Hills are higher on the Burmese side, with many mountain peaks reaching 1,000 m, while on the Thai side the highest summits remain around 600 m save few exceptions. •
Central: The southernmost extension of the Bilauktaung reaches the northern end of the Kra Isthmus. Further south the 1,835 m high
Khao Luang (เขาหลวง), located in
Nakhon Si Thammarat province, is the tallest mountain in
Southern Thailand. In this area the wider range is divided into separate ridges with gaps between them. Some recent geographical works refer to the sections of the Tenasserim Hills in the isthmus as the "
Phuket Range" and the "
Nakhon Si Thammarat Range". These names are not found, however, in classical geographic sources. •
Southern: The
Titiwangsa,
Bintang,
Tahan and
Pantai Timur Ranges form the southern section of the mountain system. The northern part is known as the
Sankalakhiri Range, formed by the smaller Pattani, Songkhla and Taluban subranges. The
main range runs approximately in a northwest–southeast orientation across the border into
Peninsular Malaysia, and forms the backbone of the peninsula, separating the
west and east coast regions. The main stretch of the Titiwangsa Mountains cover the states of
Kelantan,
Pahang,
Perak,
Selangor and
Negeri Sembilan.
Foothills extend further southeastwards into
Johor, where 1,276 m high
Mount Ophir is located. The 2,187 m high
Mount Tahan of the
Tahan Range and the 2,183 m high
Mount Korbu are the highest summits of this stretch and of the whole Tenasserim Range. ==Ecology==