Area: 6,899.5 sq. km.
Population: 740.7 habitants (2006)
Capital: Yen Bai City.
Administrative divisions:
- Town: Nghia Lo
- Districts: Luc Yen, Van Yen, Mu Cang Chai, Tran Yen, Yen Binh, Van Chan, Tram Tau.
Ethnic groups: Viet (Kinh), Tay, Dao, H'Mong...