La Negra Mine is located in the Maconí Mining District, Querétaro State, in the eastern part of the Sierra Guanajuato Gorda (Fig. 1). The nearest important town is Querétaro, 215 km southwest of the mine unit; the nearest village is Maconí, 5 km away from the mine. Access to La Negra Mine is from Querétaro on the Cadereyta-Maconi road, which takes about 2 hours. The nearest railroad station is San Nicolás, 120 km away on the México-Querétaro railroad. The mine is at an elevation of 2,000 m.
This summary is based mostly on work by José E. Gaytán- Rueda (1975), presently the Director of Peñoles Group Exploration-Mines; the Special Studies group of Industrias Peñoles, S. A., Exploration Division; and unpublished reports by the unit's Geological Department.