This area has been known for a long time. Numerous mining sites are located on the valley floor along the river. Mostly rubies
are recovered from the alluvium in open-pit mining schemes. The majority of these gems are of low-to-medium quality and in sizes of up to 5 carats.
The old Tagaung-nann-daing mine was rehabilitated and reopened in 2001. By April 2001, the mines were in full operation, expanding its open-pit mining production. In September 2001, gem mining operations at Tagaung-nann-daing were suspended due to severe flooding and by November 2003 gem mining was considerably reduced.
Ref: Ted Themelis (2008) Gems and mines of Mogok, p. 242