Montana has several volcanic features, including extinct volcanoes, volcanic fields, and lava flows. However, there are no currently active volcanoes in Montana.
The most well-known volcanic feature in Montana is probably the Yellowstone Caldera, which is a supervolcano located in Yellowstone National Park. The last major eruption of the Yellowstone Caldera occurred about 640,000 years ago and is estimated to have been one of the largest volcanic eruptions in the Earth's history.
There are also several other volcanic features in Montana, including the Medicine Lake Volcano, the Pioneer Mountains volcanic field, and the Absaroka volcanic field. However, these volcanoes are all considered to be extinct, meaning that they have not erupted in at least 10,000 years and are not expected to erupt again in the future.