Abstract The Tayoltita Mining Unit in Durango, a mining-metallurgical industry that develops silver and gold deposits owned by Compañía Minera MSL, S. A. de C. V., is located 125 km northwest of the harbor town and prominent tourist center of Mazatlán, Sinaloa, and 150 km west-northwest of Durango, capital of Durango State (Fig. 1). A commercial airline based at Tayoltita offers year-round daily flights, stopping at Mazatlán and Durango on alternate days. The bulk of the raw material for the mining-metallurgical operation, as well as heavy machinery and equipment, are landtransported on heavy trucks along the annually reconditioned Rio Piaxtla bed between San Ignacio, Sinaloa, and Tayoltita; traffic usually ceases in June at the start of the rainy season. The climate at Tayoltita is subtropical; temperatures range from a minimum of 10°C on winter nights to a maximum midday 40°C in summer. Regional annual precipitation is 69 cm, with afternoon torrential showers during the summer and lighter rains in late November and early February. The topography of the mine area is extremely rugged. Elevations fluctuate from 450 m at Tayoltita to 1,985 m at the highest mineworks in Sierra Soledad. Tablelands surrounding the Rio Piaxtla Canyon on the north, south, and east are 2,400 m high on the average, with a maximum elevation of 3,150 m at Cerro Huehuente, 19 km east of Tayoltita.