Mae Hong Son town was originally established in the early 19th century as an elephant training camp as ordered by the then King of Chiang Mai.

[7] As a result of the Anglo-Siamese Boundary Commission of 1892–1893, Mae Hong Son District was ceded to Siam,[8] but the adjacent Möngmaü and Mehsakun trans-Salween Districts also claimed by Siam (as territories on the eastern side of the Salween River), were kept as part of British Burma.

As part of the plan, the Royal Irrigation Department (RID), would build 69 metre high dam with a storage capacity of 68.7 million m3 constructed on 2,075 rai of forest land, together with a pumping station on a separate 55 rai plot and a 61.5 kilometre-long tunnel passing through 14 villages.

ONEP rejected the EIA for the second time due to concerns about forest destruction, tunnel rock waste, and compensation issues.

Further there are seven hill tribes which consists of 63% of the provincial population: Karen, Lahu, Lisu, Lua, Miao, Chinese Yunnan and Pa-O people.

To the south, it borders the district of Tha Song Yang and Tak, via the rivers Yuam and Ngao, which serve as a provincial boundary.

To the east it borders the districts of Wiang Haeng, Chiang Dao, Mae Taeng, Mae Chaem, Hot and Omkoi in Chiang Mai province, via the central and east sections of the Thanon Thongchai mountain ranges, which serve as a boundary between the two provinces.

Every district in Mae Hong Son province shares a common border, measuring approximately 483 kilometres in total length, with Myanmar.

[14] 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 rainforest.

Monsoon season runs from May through October, with heavy rain and somewhat cooler temperatures during the day, although nights remain warm.

[20] Among the minerals that have been discovered in the province are limestone, coal, lignite, lead, zinc, tin, tungsten, antimony, fluoride, and feldspar.

[22] As of 26 November 2019 there are:[23] one Mae Hong Son Provincial Administration Organisation (ongkan borihan suan changwat) and seven municipal (thesaban) areas in the province.

The non-municipal areas are administered by 42 Subdistrict Administrative Organisations (SAO) (ongkan borihan suan tambon).

The official provincial slogan promoted by the Thai government is หมอกสามฤดู กองมูเสียดฟ้า ป่าเขียวขจี ผู้คนดี ประเพณีงาม ลือนามถิ่นบัวตอง (RTGS: mok sam ruedu, kong mu siat fa, pa khiao khachi, phu khon di, prapheni ngam, lue nam thin bua tong) 'Mists throughout the three seasons, the Kong Mu (monastery) that scrapes the sky, verdant forests, gentle people, beautiful customs; renowned land of marigolds'.

[28] There are four major roads in the province:[29] Two bus companies (Prem Pracha Transport Co and Sombat Tour Co.) operate four bus services:[30] Bangkok Airways provides daily flights between Chiang Mai International Airport and Mae Hong Son Airport.