By VolcanoDB Research Team. Data: Smithsonian Global Volcanism Program, Alaska Volcano Observatory (AVO), USGS.
Why Alaska Is America's Most Volcanic State
Alaska sits at the northern end of the Ring of Fire, where the Pacific Plate dives beneath the North American Plate along the Aleutian Trench — a 3,400 km subduction zone stretching from near Anchorage to the far western Aleutians, just 300 km from Russia. That subduction produces one of the densest concentrations of active volcanoes on Earth.
The numbers are staggering. Alaska accounts for roughly 80% of all US volcanic eruptions and 8% of the world's historically active volcanoes. Most sit along the Aleutian arc, but the Wrangell volcanic field in southeast Alaska and scattered volcanic centers along the Alaska Peninsula extend the volcanic zone across 3,000+ km of coastline. Sixty-one of Alaska's 87 database volcanoes are stratovolcanoes, the steep-sided explosive type that dominates subduction zones.
Most Active Alaska Volcanoes — From Our Database
Here are Alaska's most active volcanoes ranked by eruption count in our Smithsonian-sourced database, with current AVO alert levels as of June 2026.
Current AVO Alert Levels (June 2026)
The Alaska Volcano Observatory monitors over 50 volcanoes with seismometers, GPS, satellite imagery, and infrasound sensors. As of June 2026, three volcanoes have elevated alert levels:
Novarupta 1912: The Largest Eruption of the 20th Century
The single most important volcanic event in Alaska's recorded history — and one most people have never heard of. On June 6, 1912, Novarupta erupted with a VEI 6 blast that ejected 15 km³ of material over 60 hours. That's 30 times the volume of the 1980 Mount St. Helens eruption.
Pyroclastic flows filled the adjacent Ukak River valley with ash deposits up to 200 meters thick, creating what botanist Robert Griggs named the Valley of Ten Thousand Smokes when he explored it in 1916 — thousands of fumaroles vented steam through the still-hot deposit. The eruption also drained magma from beneath nearby Mount Katmai, collapsing its summit into a 3 km-wide, 600 m-deep caldera that now holds a lake.
Ash fell on Kodiak (160 km away) for three days, collapsing buildings under the weight. The town went dark at noon. Acid rain burned clothing and dissolved fabric. But remarkably, nobody died — the area was so remote that the nearest community had already evacuated when the earthquakes started. Had Novarupta been near a major city, it would have been one of the deadliest eruptions in history.
Notable Alaska Eruptions
Beyond Novarupta, Alaska has produced some remarkable eruptions:
Redoubt 1989: The December 15 eruption sent an ash cloud directly into the path of KLM Flight 867, a Boeing 747 carrying 231 passengers. All four engines failed at 27,000 feet. The plane dropped nearly 14,000 feet before pilots restarted the engines. Everyone survived, but the incident cost $80 million in damage and rewrote aviation safety protocols for volcanic ash worldwide.
Redoubt 2009: Nineteen eruptions in five months, with ash columns reaching 60,000 feet. The eruption destroyed monitoring equipment, forced flight cancellations across south-central Alaska, and dropped ash on Anchorage. Oil facilities in Cook Inlet shut down.
Bogoslof 2016–17: A submarine eruption that repeatedly built and destroyed a small island in the Aleutians. Over 70 explosive events in 9 months, with some producing volcanic lightning. The eruption reshaped the island's coastline multiple times — a perfect example of volcanic island formation in real time.
Augustine 1986: The eruption was significant for volcanology — it was one of the first where scientists successfully used GPS and tiltmeters to track magma movement in real time. The island volcano in Cook Inlet produced pyroclastic flows that extended to the coastline and generated small tsunamis in Cook Inlet.
Aviation Hazard: Why Alaska's Volcanoes Affect Flights Worldwide
Here's something most people don't realize: about 50,000 airline passengers fly through Alaska's airspace every day on great-circle routes between North America and Asia. Volcanic ash is invisible to aircraft weather radar and can sandblast windshields opaque, clog engine cooling systems, and melt inside jet engines (silicate glass solidifies on turbine blades, causing flameout).
That's why AVO exists. It's not just about protecting Alaskans — it's about protecting international aviation. The observatory issues four-tier aviation color codes (GREEN, YELLOW, ORANGE, RED) mirroring volcanic alert levels. When Shishaldin, Cleveland, or Pavlof produce ash clouds, flights divert or cancel. A single Alaskan eruption can delay hundreds of flights between the US and Asia.
Visiting Alaska's Volcanoes
Alaska's volcano tourism is nothing like the lower 48. There are no paved roads to most volcanic sites, no visitor centers at the crater rim, and the weather can ground your bush plane for days. That's the tradeoff — and it's what makes Alaska's volcanoes extraordinary. Check our volcano hiking safety guide before planning backcountry trips.
The Valley of Ten Thousand Smokes — site of the 1912 Novarupta eruption — is the centerpiece. A bus tour ($96 round-trip from Brooks Camp) takes you across 40 miles of volcanic landscape to a 700-foot-deep ash deposit still largely barren after 114 years. But most visitors come for the bears: Brooks Falls in July has the densest brown bear viewing in the world. There are no roads to Katmai — you fly in from King Salmon or Homer.
Cost: $10/day (camping). No entry fee. Float plane ~$300-600 round trip.Best time: June–September. Bears peak at Brooks Falls in July.
Redoubt and Iliamna volcanoes dominate the skyline across Cook Inlet from Anchorage. Lake Clark is one of the least-visited national parks (fewer than 18,000/year), which means you'll have volcanic landscapes mostly to yourself. Bear viewing at Chinitna Bay rivals Katmai at a fraction of the crowds. Again, no roads — fly in from Anchorage, Homer, or Kenai.
Cost: Free entry. Float plane ~$400-800 round trip from Anchorage.Best time: June–September. Bear viewing peaks in July.
Wrangell-St. Elias National Park
The largest national park in the US (13.2 million acres) contains Mount Wrangell — one of the largest active volcanoes in Alaska with a 6 km summit caldera containing heat vents that melt ice craters. Unlike most Alaska volcano parks, you can actually drive into Wrangell-St. Elias via the McCarthy Road (60 miles of gravel, passable in summer). The Kennecott copper mine ruins add a historic dimension.
Cost: Free entry. McCarthy Road is free but rough.Best time: June–September. McCarthy Road typically open May-October.
Volcano Flightseeing from Anchorage
If your time is limited, flightseeing is the best way to see Alaska's volcanoes. Multiple operators run flights from Anchorage over Redoubt, Iliamna, and Augustine on clear days. Some tours combine volcano views with glacier landings. Flight time is typically 2-4 hours. On a clear day, you can spot Redoubt's steaming summit from downtown Anchorage across Cook Inlet.
Cost: $250–500/person. Book 2+ weeks ahead in summer.Best time: May–September. Clear-weather days only.
Explore All 87 Alaska Volcanoes in Our Database
Full eruption history, elevation data, and current monitoring status for every volcano in the state