The USA is one of the most volcanically active countries on Earth, with a total of 161 "potentially active" volcanoes according to the USGS Volcano Hazards Program. These range from mighty mountains that have erupted in the last few years – including Hawaii’s Kilauea and Mauna Loa – to volcanic areas filled with geysers and hot springs.
Click through this gallery to discover the most active volcanoes in America...
Until its historic eruption in 1980, Mount St Helens had a conical shape and was dubbed the "Mount Fuji of America." But despite lying dormant since 1857, on March 27, 1980, it had an explosive steam eruption, triggering an earthquake that registered at 5.1 on the Richter scale and led to a huge landslide.
The impact was catastrophic: 57 people were killed and a 200-plus-square-mile area of trees was razed. Surrounding valleys were also buried in lava flows. Since then, seismic activity has been recorded on numerous occasions, although there hasn't been another major eruption.
You only need to stroll through the Long Valley Volcanic Center to see that it’s a hub of volcanic activity, with wonders from geothermal pools to lava domes and steaming fumaroles (pictured). The natural landscape, located east of California’s central Sierra Nevada Mountains, burst into life after a giant eruption around 760,000 years ago.
Ongoing activity created features including the geothermal Hot Creek, around 288,000 years ago, as well as Mammoth Mountain, between 111,000 and 57,000 years ago. The most recent eruption here was just 300 years ago, while the area is frequently shaken by earthquakes.
Located in southern Alaska’s Chigmit Mountains, Redoubt is an active stratovolcano that most recently erupted in 2009. Between March 15 and April 4 that year, major explosions led to rock falls and small plumes of ash, while the size of the lava dome increased.
However, its most infamous eruption took place between 1989 and 1990 (pictured in April 1990), creating more than $160 million in damages and making it America’s second-most expensive eruption of all time. The peak, which is considered one of Alaska’s most dangerous volcanoes, was largely formed within the last 200,000 years.
Northern California’s picturesque Mount Shasta is fast becoming a popular vacation destination, with brilliant options for hiking, mountaineering, and skiing. But it’s still an active volcano, averaging one eruption every 600 to 800 years.
It was formed from the remnants of an older volcano around 300,000 to 500,000 years ago, and there are still volcanic gases and hot springs emitting from the summit, with the USGS currently giving it a "Very High" threat level.
A glaciated peak which stands at 10,016 feet near the mouth of Cook Inlet, Iliamna last erupted in 1867. However, there have been reports of vapor, smoke, and possibly ash issuing from the volcano several times throughout the 20th century, most recently in 1958.
The cone-shaped peak is made up of volcanic rocks and lava flows and is surrounded by 10 glaciers. It is currently on "Normal" alert level, according to the Alaska Volcano Observatory.
A trio of closely spaced volcanoes in Oregon’s Cascades Range, the Three Sisters were formed between 120,000 and 50,000 years ago. The most recent eruption was around 2,200 years ago.
However, in February 2022 scientists reported movement in the volcanic region, which included slight ground uplift and small earthquakes. These three stratovolcanoes are considered to have a "Very High" threat level, according to the USGS.
With its dome-like peak casting a memorable silhouette across western Washington, Mount Rainier stands at a towering 14,410 feet above sea level. As well as being an active volcano, it’s America’s most glaciated peak, offering an adrenalin-pumping challenge for the thousands of mountaineers who climb to its summit each year.
Although it hasn’t had a significant eruption for around 500 years, it is considered the most dangerous volcano in the Cascades range. That’s because it’s covered with such an immense mass of ice and snow, that if even a small quantity is melted by an eruption, it could lead to enormous and highly destructive mudflows.
The highest point on the island of Umnak, in Alaska’s Aleutian Arc, Vsevidof towers 7,051 feet above sea level. The peak, which contains a 0.75-mile wide summit crater, had its last confirmed eruption in 1878, although an eruption was reported in 1957 when local residents observed steam and ash emitting from the volcano.
It’s thought that the volcano is geographically young, with the majority of it being formed in the Holocene (the last 11,700 years).
Another volcano found in the Aleutian Islands is the mighty Makushin. The 5,906-foot ice-covered peak most recently erupted in 1995, when a small cloud of ash and steam was emitted from the peak and minor tremors were felt in the surrounding area. The hike up the 2,300-foot Pyramid Peak is popular and offers a spectacular vantage point from which to drink in views of Makushin.
The largest volcano in the Cascades range, Newberry covers an enormous 1,200 square miles and stands at a colossal 7,986 feet tall. Although it hasn’t had an eruption since AD 690, the presence of young lava flows and hot springs show that it is still active, with the USGS rating its threat level as "Very High."
With more than 200,000 people living nearby, in the surrounding towns of Bend, Sunriver, LaPine, and Redmond, scientists are closely monitoring the mountain in case of a future explosion.
An iconic feature of the Pacific Northwest landscape, Oregon’s Mount Hood has been active for at least 500,000 years. The most recent period of activity occurred between 1859 and 1865, when witnesses reported smoke, fire, flying rocks, and steam emitting from the peak.
Prior to this there was a significant period of activity some 1,500 years ago. Today, the volcano’s threat level is considered "Very High" and it is closely monitored by the USGS.
Situated around 80 miles west of Anchorage, Mount Spurr towers at 11,070 feet in elevation and is the easternmost active volcano in the Aleutian Arc.
Its most recent eruption occurred in 1992, when the surrounding area was blanketed in a carpet of ash around eight inches thick, while the city of Anchorage came to a standstill for several days. Closely monitored by the Alaska Volcano Observatory, the peak currently has a "Normal" alert level in place.
Some 350,000 visitors come to Lassen National Park each year to admire its otherworldly landscapes, which encompass steaming fumaroles to hydrothermal lakes and mud pools.
The dynamic region is home to four different types of volcano: composite, shield, plug dome, and cinder cone. The most recent notable eruption here was between 1914 and 1915, when Lassen Peak spewed a column of ash that reached some 30,000 feet into the skies, while melting snow led to flooding and mudflows up to 30 miles away.
Located in the Aleutian Islands off the southwest coast of Alaska, Akutan is a composite stratovolcano that stands at 4,275 feet above sea level. Inside the 1.2-mile caldera, which was formed by an eruption around 1,600 years ago, there are three crater lakes as well as small glaciers, ice cliffs, and snow fields.
It has erupted at least 27 times since 1790, with the most recent explosions occurring in the late 1980s and into the early 1990s.
Towering 4,134 feet above sea level on an island in Alaska’s Cook Inlet, Augustine is the most active volcano in the eastern Aleutian Arc. Its most recent eruption was in 2006, when a series of 13 short blasts over a three-week period triggered avalanches, pyroclastic flow, and lahars. Volcanic activity has been frequent through the past two centuries, with notable eruptions in 1812, 1883, 1935, 1963-64, 1976, and 1986
Just 14 miles south of the US-Canada border in Washington state lies the colossal 10,780-foot peak of Mount Baker. Formed between 40,000 and 10,000 years ago, this active stratovolcano could trigger lahars, debris flows, and landslides if it erupts, due to its steep terrain and the high coverage of ice and snow.
It last erupted in 1843, which led to the formation of Sherman Crater, while surrounding rivers were filled with ash and forest fires were spotted for miles around.
One of Hawaii’s youngest volcanoes is Hualālai, a shield volcano located on the northwestern side of the Big Island. Rising to 8,271 feet above sea level, the peak was largely formed during the Holocene era – in fact more than half of it is less than 3,000 years old.
Although its last eruption was in 1801, making it far less active than neighboring Mauna Loa and Kilauea, experts say that the peak is likely to erupt again, with the USGS classifying it as a high threat volcano.
Washington’s Glacier Peak certainly lives up to its name: it’s flanked by more than a dozen glaciers, which makes it a popular spot for hiking and mountaineering. Formed around one million years ago, it has produced some of the largest explosive eruptions in the US since the end of the last ice age and has erupted at least twice in the past 2,000 years.
Due to this history of volcanic activity, Glacier Peak’s threat level is rated as "Very High" by the USGS.
In late November 2022, the world’s largest active volcano, Hawaii's Mauna Loa, rumbled back to life. The explosion, which saw lava break to the caldera’s surface for the first time in 38 years, caused 200 million to 250 million cubic meters of lava to flow from the summit, traveling up to 12 miles.
It was initially feared that the busy Daniel K Inouye Highway would be blocked by flows, but they stopped a mile and a half short of the road. On March 16, Mauna Loa’s alert level was downgraded from yellow to green by the Hawaiian Volcano Observatory, following three months of inactivity.
Created by the eruption of the 12,000-foot Mount Mazama volcano around 7,700 years ago, Crater Lake has enthralled visitors for thousands of years. At 1,943 feet deep, the natural wonder is the deepest lake in America, while it owes its bright blue hue to the fact that it’s fed entirely by melted snow and rainfall. This makes it one of the world’s cleanest lakes.
Although it might look like a peaceful bathing spot, it’s still an active volcano, with a threat level rated as "Very High" by the USGS.
The most recent eruption of Alaska’s Mount Okmok took place in August 2008, sending a huge column of ash into the skies and creating a large cloud over the ocean. Located on Umnak Island in the east of the Aleutian Arc, the colossal mountain had its first massive eruption in 43 BC.
In fact, it’s thought that this eruption could have contributed to the fall of the Roman Republic: it brought about extremely cold temperatures, which led to crop failures, disease, and famine. At present, Okmok is being monitored by the Alaska Volcano Observatory and has a "Normal" alert level.
Many features situated on the Yellowstone Caldera draw in visitors from all over the world, including the Old Faithful Geyser, the vibrant Grand Prismatic Spring, and the enormous Yellowstone Lake. But beneath them looms a giant supervolcano. It has only had three major eruptions in history – one 2.1 million years ago, one 1.3 million years ago, and one 664,000 years ago.
And while one study says that an eruption could blanket large parts of the Midwest in a layer of ash, the USGS notes that it’s far more likely that the volcano will have a hydrothermal or lava flow eruption, most of which are not highly explosive.
Also known as Chuginadak, Cleveland Volcano is a symmetrical stratovolcano that soars to 5,676 feet. It resides on the western side of Chuginadak Island, in the Aleutian Arc, and is one of the most active volcanoes in the archipelago.
Frequent ash plumes from eruptions have caused disruptions to air traffic in recent years, while it was also responsible for the only known fatality from an eruption in the Aleutian Islands, in 1944. It's pictured here during an eruption in 2009.
In December 2024, Kilauea volcano in Hawaii started erupting – and continued to do so deep into 2025. Fountains of lava shot repeatedly from vents in the summit crater, but fortunately no lava escaped onto the volcano's slopes.
The peak, which is the youngest and most active volcano in Hawaii, has frequent non-explosive eruptions, as well as occasional dramatic flows: in 2018, a long-lasting eruption created streams of lava that destroyed some 700 homes.