The dominant indigenous group in San Luis Potosí today is the Huastecs, also known as the Teenek, which means “those who live in the fields with their language, their blood and share the idea.” Most of this population lives in the eastern portion of the state in the Pánuco river basin, which covers 10,238 square kilometers (4,000 square miles) and is distributed among 18 municipalities. The Teenek share the basin area with the mestizos (mixed race) and the Nahuas, who inhabit the southern portion of the region. Most of the Teenek population lives in the Aquismón, Tanalajás, Ciudad Valles, Huehuetlán, Tancanhuitz, San Antonio, Tampamolón and San Vicente Tancuayalab municipalities.