Cool outcrop near Twin Sisters (City of Rocks, Idaho) exposes the interplay of two granites.

Check out the Twin Sisters area at City of Rocks National Reserve with geology professor Shawn Willsey. Here we investigate a spectacular outcrop about 0.5 miles southeast of the Twin Sisters and right next to the historic California Trail. Much like the Twin Sisters themselves, this fascinating location exposes the relationship between the Archean (2.5 billion years old) granite and the much, much young (28 million year old) granite of the Almo Pluton. You can learn more about southern Idaho geology by purchasing Geology Underfoot in Southern Idaho and Roadside Geology of Idaho. Both available locally or on Amazon. I love doing these videos and will continue to do so but if you want to provide support or much appreciated gas money, you can send support via: Venmo @Shawn-Willsey (be sure to put two L's in last name) or PayPal: https://www.paypal.com/donate/?hosted... or a good ol' fashioned check to this address: Shawn Willsey College of Southern Idaho 315 Falls Avenue Twin Falls, ID 83303