20 September 1983.
México, Mexico
Locality: Along Hwy 55, Toluca to San Juan del Rio, 7 km N of Acambay, on slopes surrounding a shooting range site to the E of the road.
Coordinates: 19.9500, -99.8500
(Map it)
Elevation: 2750m.
Environment description: 45 degree slope in hilly area dominated with pines and oaks; light brown soil with white calcareous stones and rocks.