July 19, 5:30PM - July 19, 6:30PM

More than a billion years ago, a huge bubble of 2,000 degrees Fahrenheit magma got trapped 10 kilometers beneath our feet and began to cool.  Learn what happened as the last bit of magma finally turned into solid rock. Presented by Dan Gruber, legacy steward of the McDowell Sonoran Conservancy. Go to McDowellSonoran.org for information.