Hawaii
There are several volcanoes in Washington, a few of which have already had eruptions in recorded history, most famously the 1980 eruption of Mount St Helens. Washigton's volcanoes are a result of the Cascadia Subduction Zone, where two of Earth's tectonic plates collide.
shield volcanoes
No state name means Home of the Volcanoes.
Alaska is the US state with the most volcanoes.
The Mount Tambora eruption occurred in the state of West Nusa Tenggara in Indonesia.
Many states don't have a single volcano so it's hard to tell which state has the least amount of volcanoes.
Hawaii
Dotsero is a cinder cone volcano located in Colorado, USA. It is known for being one of the youngest volcanoes in the state, with its last eruption occurring approximately 2200 years ago. Dotsero is classified as a monogenetic volcano, meaning it only erupts once.
The study of volcanoes: volcanology is important because volcanic eruptions can cause immense damage to the surrounding area: when Mount Saint Helens erupted in 1980 65 people died in the ensuing mud slides. Volcanoes are studied by examining the magna (hot molten rock, lava is erupted magma) in the volcano which is located in the crater, most volcanoes don't even have craters. Mostly volcanoes are studied by monitoring their state and trying to correlate changes that can be used a as a predictor for an eruption.
Hawaii is the US state that has two active volcanoes, Kilauea and Mauna Loa. Both volcanoes are located on the Big Island of Hawaii and are part of the Hawaii Volcanoes National Park.
Hawaii still has five active volcanoes to this day!