Pico de Orizaba
In 1888, Heilprin was in Mexico, where he ascended volcanos: Ixtaccihuatl, Nevado de Toluca, Pico de Orizaba and Popocatepetl, establishing their altitudes with barometric measures. He also shed light on questions about the geology of the Yucatan and the coral reefs of the western Gulf of Mexico.