The Thanon Thong Chai Range (Thai: เทือกเขาถนนธงชัย, formerly Thanon Range; Burmese Tanen Taunggyi) is a mountain range in Northern Thailand. Its tallest peak is Doi Inthanon, the highest point in Thailand. Most of the range is located in Chiang Mai Province, with parts in Mae Hong Son and Lamphun Provinces.Geologically in the Thanon Thong Chai Range, as in the other southern subranges of the Shan Hills, layers of alluvium are superimposed on hard rock.