Description: This episode, number eight in our Yosemite National Park series, is for the geology geeks and climbing enthusiasts. If neither of those monikers interests you right now, just wait: you’ll want to pick up a rock hammer or clip yourself to a rope by the end of the show -- possibly both! To start, Bryan chats with Park Geologist and Ranger Greg Stock on the forces that shaped Yosemite’s stunning scenery and the toll our warming climate is having on the park. Then, Danielle dives into mountaineering with Dave Bengston, director of Yosemite Mountaineering School, to learn about the highs and lows of this perennially popular park activity.   Discussion includes the following: 0:01 - Introduction to the episode’s guests: Yosemite’s Park Geologist and Ranger Greg Stock and Dave Bengston, director of Yosemite Mountaineering School, plus Danielle reads a sweet note from a listener. 2:54 - Bryan exposes a geologist’s best-kept secret and gets to know Greg Stock 4:08 - Fatal rockfalls and shifting attitudes toward climate challenges drive the National Park Service to hire a geologist for Yosemite National Park (https://www.nps.gov/yose/index.htm) 5:44 - A geological timeline: The formation of Yosemite’s iconic granite peaks El Capitán, Half Dome, Cathedral Peak, Lembert Dome, and Pothole Dome 7:26 - The Merced River (https://www.nps.gov/yose/learn/nature/mercedriverrestoration.htm) 8:10 - A closer look at the processes of exfoliation, glacial erosion, and rockfalls (https://www.nps.gov/yose/learn/nature/rockfall.htm) 9:41 - The dynamic, year-round forces that trigger rockfalls 12:29 - Quantitative rockfall hazard risk and assessment and front-country campsite safety; an incident at Curry Village (2008) 15:20 - Yosemite’s fading ice: The Lyell and Maclure glaciers 16:38 - Replicating John Muir’s 1872 Maclure glacier survey 18:22 - The alarming truth about the future of Yosemite’s glaciers