08 September 1983.
Hidalgo, Mexico
Locality: From Las Trancas on Hwy 85, Zimapan to Jacala, about 7 km E towards Nicolas Flores, then 2 km NE on the track to Puerto de Piedra.
Coordinates: 20.8667, -99.2667
(Map it)
Elevation: 2520m.
Environment description: Mountainous area; loose rocks and red soil; steep S-facing slope below the road.