58.35 N, 155.10 W
summit elevation 2317 m
Griggs volcano is located in Katmai National Park, on the NE side of the Valley of Ten Thousand Smokes, Alaska. Mount Griggs is situated 12 km behind the main volcanic chain that includes Katmai, Trident, Mageik, and Martin.
Griggs volcano contains three nested summit craters, two of which are on top of a Holocene central cone. Mt Griggs volcano is better preserved than many stratovolcanoes in the region.
Fumaroles are present in the summit crater and SW flank. A dacite scoria flow at base of Mount Griggs originated from Katmai volcano.
Pyroclastic flow deposits
Three glacially eroded remnants of pyroclastic flow deposit are located at the southern base of Griggs volcano in upper Knife Creek. The flow is up to 10 m think, and consists of scoria lapilli mostly 1-2 cm diameter.
Basaltic scoria fall
A scoria fall outcrop ,1 m thick, 5 m across, and 25 m long, is located at the southern base of Griggs volcano. The pumice originated from Katmai volcano.
3460 years ago.