09 September 1958.
Zacatecas, Mexico
Locality: Km 734.5 from Mexico City on the Aguas Calientes-Zacatecas road, 14 km from Zacatecas, E side of the road.
Coordinates: 22.7833, -102.5833
(Map it)
Elevation: 2200m.
Environment description: Maize field.