Mount Kaguyak is a stratovolcano located in the northeastern part of the Katmai National Park and Preserve in the U.S. state of Alaska. The 2.5 km wide caldera is filled by a more than 180 m deep crater lake. The surface of the crater lake lies about 550 m below the rim of the caldera. Postcaldera lava domes form a prominent peninsula in the center of the lake. The volcano is 901 m high and is topographically prominent because it rises from lowland areas near sea level in the south of the Big River. Based on radiocarbon dating the caldera-forming eruption occurred about 5800 years before present. During this eruption at least 120 sqkm were covered in a dacitic ignimbrite.