The Guanajuato's River is a tributary of the Lerma River in the central near region of Mexico called the Bajio (Lowlands). The river begins in the silver-rich Guanajuato mountains near the state capital of Guanajuato. The river is fed by the Guanajuato river basinca (in Spanish: cuenca) (a sub-basin to the much larger Lerma–Chapala Basin) and has an area of 3,320 km², which makes up approximately 10.32% of the total area of the state. There are approximately 900,000 people living in the Guanajuato River basin area, in the municipalities of Guanajuato, Irapuato, Romita, San Francisco del Rincon, Manuel Doblado and Pueblo Nuevo.