Cochise County sits in the Southeast corner of Arizona
adjacent to New Mexico and Sonora, Mexico.
The San Bernardino Valley with its volcanic field is located in the southeast
corner of Cochise County.
The San Bernardino volcanic field actually extends a short distance into Mexico.
Within the volcanic field
there are dozens of eroded cinder cones, two maars, and obvious lava flows.
Due to the rapid manner in
which basalt chemically weathers in this semi-humid environment there is plenty
of rust-colored volcanic
rocks. The youngest of the volcanoes is about 300,000 years old.
Some of the oldest features in the volcanic
field date back about 5 million years.
photo credits: Google Earth, Digital Globe, INEGI