Tuyên Quang Province
Caolan is spoken by the Cao Lan-Sán Chay people of Tuyên Quang Province. According to the people, the Cao Lan and Sán Chay peoples had arrived from southern China 400 years ago together as one group, even though they spoke two different languages. Notably, they both use Chinese characters to record their languages. Smaller numbers are also found in the following provinces (Gregerson &amp; Edmondson 1998).