The treeless summit of Panorama Dome offers a unique perspective on the "fire and ice" geology that caused the area to look as it does today--right from the heart of the action. During the last major ice age, from about 25,000 to 12,000 years ago, a huge cirque glacier worked to scoop out what is now the Lakes Basin, pushing rocks and debris out into the Mammoth Creek Valley through a gap between the existing volcanic mountains. Panorama Dome now stands in that gap, strewn with evidence of what is known as lateral moraine, like a dyke between the Lakes Basin and the enormous volcanic caldera beyond.