Carson Pass Geology Walk – Fire and Ice! Join naturalist Marc Hoshovsky at Carson Pass to learn about the area’s fascinating geology. We’ll take a leisurely 1.5-mile (one-way, 300’ elevation gain) walk, with multiple stops, to Frog Lake and its Hope Valley vista. Along the way, you’ll see 90-million-year-old granite, metamorphic rocks older than the dinosaurs, ancient volcanoes and mudflows, Ice Age glacial moraines, and the 2,000’ uplift of the Sierra on the Red Lake Fault.