General · EdgepediaOctober 20, 20263 min read

Dângrêk Mountains

The Dângrêk Mountains (Khmer: ជួរភ្នំដងរែក, Chuŏr Phnum Dângrêk; Thai: ทิวเขาพนมดงรัก, RTGS: Thio Khao Phanom Dongrak) are a mountain range along the border between Thailand and Cambodia, forming that boundary's natural spine across mainland Southeast Asia.¹ The range separates Thailand's northeastern Isan region from Cambodia and runs eastward to the tripoint where Thailand, Laos, and Cambodia meet.²^•³

Key fact	Detail
Conservation	The Dangrak ecological corridor links Thailand's Dong Phayayen-Khao Yai Forest Complex to Cambodian protected areas and southern Laos⁴

Geography

Despite its length, the Dângrêk is a low mountain system, with average summit heights of about 500 meters. The highest peak, Phu Khi Suk, rises to 753 meters and is not prominent at the eastern end of the range. Other named summits include Phu Khok Yai (693 m), Phu Chep Thong (692 m), Phu Tangok (689 m), Pha Lan Sur (670 m), Phnom Aen Nak (638 m), Phnom Tabal (582 m), and Khao Banthat (374 m) at the western end.⁸

The range's profile is strongly asymmetric. The northern side slopes gently toward the Khorat Plateau of Thailand, while the southern face is typically a steep escarpment covering the plains of northern Cambodia. The watershed along this cliff line is generally treated as the international boundary, though there are exceptions: the main road connecting the two countries cuts through a pass in the mountains at O Smach, a small administrative district of Thailand's Surin province.

Geology

A Cambodian government environmental assessment describes the Dangrek Mountains as limestone mountains along the northern border with Thailand, notable for historical sites such as the Preah Vihear Temple; the two descriptions differ on the dominant rock type.⁵

The range's modest height reflects deep erosion of an ancient surface, while its abrupt southern edge is one of the most distinctive geological features in mainland Southeast Asia.⁶

History

Khmer Empire. The Dângrêk range once formed part of the ancient Khmer Empire, which expanded northward and reached its peak of control over nearly all of the Isan area in 1220, in the reign of Jayavarman VII. Angkorian transport geography gave the passes through the 500-meter-high Dangrek escarpment political value, and the Khmer road system connected through them.⁷

Conservation

The Dangrak ecological corridor straddles the Thai-Cambodian border and is an area of regional conservation importance. The landscape connects Thailand's Dong Phayayen-Khao Yai Forest Complex with conservation zones and wooded terrain running along the frontier shared by Thailand and Cambodia, and reaches east into the southern part of Laos. Much of the landscape exists under formal protection, but managers and rangers lack the resources and capacity to prevent illegal activities. Poaching is rife, with high-value species particularly targeted for trafficking, and transnational organized criminal networks exploit vulnerable communities by encouraging their participation in trafficking of all forms.⁴ A conservation program running from 2023 to 2025, led by the Freeland Foundation with support from Fondation Segré, works to protect the corridor.⁴

Names

The range is recorded under many spellings and forms, including Chaîne des Dangrek, Chuor Phnum Dangrek, Dangrek Range, Phanom Dong Rak, Phnom Dang Rek, and Thiu Khao Phanom Dong Rak.¹

References

Topic: Encyclopedia › Places and geography › Landforms and terrestrial features › Mountains, plains, and other land terrain › Mountain ranges, ridges, and hill systems › Asian ranges

Initially written Oct 20, 2026 · Edited: Oct 25, 2026

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