Ice Peak, high, which overlaps the northern flank of Armadillo Peak, began to form during Edziza's third phase of activity, starting 1,600,000 years ago when the regional Cordilleran Ice Sheet began retreating. It is a stratovolcano that was constructed when large areas of the Edziza lava plateau were free from glacial ice and now enclosed by glacial deposits. However, additional parts of the Mount Edziza volcanic complex were likely still covered by glacial ice. The volcanic activity from Ice Peak during this period produced both basic and intermediate to light-coloured lava flows and pyroclastic rocks which mixed with meltwater to produce debris flows. As Ice Peak began to form, basic lava spread to the flanks of the cone where it formed meltwater lakes and combines with and forms part of the adjacent shield volcano. As lava continued to flow into these meltwater lakes, pillow lava and solidified rubble was created. Many of the lava flows with compositions of trachyte and basalt were however erupted just below the surface of the soil. Continuous volcanic activity eventually made Ice Peak reach an elevation of when three viscous, intermediate, and light-coloured lava flows built up around secondary lava domes parallel with its western side during its final stage of activity 1,500,000 years ago and develops nearly all of the steep, higher flanks of the volcano. These viscous light-coloured lava flows are displayed at two cliffs with broad faces, known as Ornostay Bluff and Koosick Bluff and contain basic rock made of solidified rubble overlain by large fractured lava with massive, poorly established pillars.