The Thai highlands or Hills of northern Thailand is a mountainous natural region in the north of Thailand. Its mountain ranges are part of the system of hills extending through Laos, Burma, and China and linking to the Himalayas, of which they may be considered foothills. The highlands in the north of Thailand are characterized by a pattern of generally steep hill ranges, intermontane basins and alluvial gorges. Elevations are generally moderate, little above for the highest summits. There is a wide range of elevations though, with floors ranging between above sea level. Towards the Lao border, the divide to the Mekong basin becomes higher with peaks occasionally rising above and streams flowing in narrow steep valleys. The climate is typical of tropical mountains with clearly delineated wet and dry seasons. Winter temperatures can be cool with frosts occurring most years at higher elevations, but no snow even on the highest peaks. The region of the Thai Highlands encompasses the nine administrative provinces of northern Thailand, based on the six-region system, as well as parts of Tak and Sukhothai Provinces. Some areas of the highlands are sparsely populated. Geography Except for the Daen Lao Range (ทิวเขาแดนลาว) at the far northern edge, all ranges in the north of Thailand are roughly aligned from north to south. They are linked to a wide system of ranges in neighboring Burma and Laos that do not have a specific name for the whole, "Thai highlands" being the term generally restricted to the Thai area. Broadly defined, and based on their geological composition, there are two mountainous subsystems in Northern Thailand: In the western part the ranges stretching southwards from the Daen Lao Range, in the southern region of the Shan Hills or Shan Highland, with the two parallel mountain chains of the Thanon Thong Chai Range (เทือกเขาถนนธงชัย). This area has the highest elevations, with Doi Inthanon, the highest point in Thailand, reaching . The Dawna Range (ทิวเขาดอยมอนกุจู) forms the western border of Thailand between Mae Hong Son and the Salween River, The remaining mountainous region of parallel ranges that extend into northern Laos includes the Khun Tan Range (ทิวเขาขุนตาน), the Phi Pan Nam Range (ทิวเขาผีปันน้ำ), the Phlueng Range (ทิวเขาพลึง) as well as the western part of the Luang Prabang Range (ทิวเขาหลวงพระบาง). A great part of the highland area is drained by rivers Ping, Wang, Yom and Nan, all tributaries of the Chao Phraya River