The Molango Manganese District covers an approximate area of 1,250 km2 in northeasternmost Hidalgo State (Fig. 1). In spite of the extensive erosion of the orebody, vast manganese ore volumes are spread over approximately 180 km2 (Frakes and Bolton, 1984).
The center of the area, which includes the villages of Molango, Xochicoatlan, Lolotla, Tepehuacan, and Tlanchinol, is at 98°45′W and 20°55′N. The Tetzintla area, presently under development, is located in the northern part of the Manganese District, about 20 km north of Molango (Hidalgo), at 90°41′15″W, and 20°57′30″N. The paved Mexico-Tampico short route crosses the district from south to north; at “Las Casetas” on km 157, a 16-km paved roadway connects the Tetzintla Mine with the Compañía Minera Autlán's industrial and housing (Otongo) areas.