About 6,800 years ago, the collapse of Mt. Mazama left visible evidence of the mountain’s former form in the steep caldera walls, which reveal its interior before the fall. From this point, several pre-collapse volcanic features can be identified. Llao Rock, the massive gray monolith on the rim ahead, formed when a large outpouring of lava filled an explosion crater on the north slope of Mt. Mazama. When the mountain collapsed, part of the hardened lava flow broke off and fell into the caldera, leaving the downslope portion perched on the rim. In the foreground, the jagged, colorful spires of Hillman Peak are the remains of a secondary volcano that erupted on the side of Mt. Mazama. This satellite cone reached a height of 1,000 feet, and erosion has exposed a maze of clogged and solidified lava conduits that fed the Hillman volcano.