The Municipality of Río Grande is one of the 58 municipalities of the State of Zacatecas, Mexico. It is the fifth most populous municipality of the State and has a territorial extension of 1,814 km². The municipal seat is the City of Rio Grande. It borders with the municipalities of Juan Aldama, Francisco R. Murguía, Saín Alto, Fresnillo, Villa de Cos, Cañitas de Felipe Pescador, Miguel Auza, Sombrerete. Cradle of the revolutionary, agrarista leader and Governor of the State of Zacatecas in 1928, Mr. D. Alfonso Medina Castañena. His remains are deposited in the Mausoleum of the Illustrious Men of Cerro de la Bufa, in the capital city of the State.
The city has some historical monuments of the colony, old adove buildings with mortar and baroque parishes are the oldest structures in this city. The City of Rio Grande is considered the Granero de la Nación because it is the largest city in the north of the State and, besides being on the border of the Frijolera Zone, it becomes the city where most of the beans are sold, in order to be able to be taken to all points of the Mexican Republic.