23 September 1983.
Zacatecas, Mexico
Locality: Hwy 45, 18 km NW of Sombrerete towards Vicente Guerrero, at junction with side-track to El Alamo.
Coordinates: 23.6333, -103.6500
(Map it)
Elevation: 2380m.
Environment description: Open juniper scrub; under Juniperus.