Most of the areas of Mae Hong Son Province are the complex mountain ranges of the Thai highlands, parts of which are still covered with rain forest.
The Daen Lao Range located on the northernmost portion of the province marks the northern boundary between Thailand and Burma and the Dawna Range in the west as a boundary between Thailand and Burma. The Thanon Thongchai Range in the east of the province serves as the boundary between the provinces of Mae Hong Son and Chiang Mai. The tallest point of the Province is Doi Mae Ya (ยอดเขาแม่ยะ) in the Pai District in the province's northeast, at 2005 metres above sea level.[2]