what's the tallest volcano in the united states?
<answer> Mauna Loa <context> United States (Hawaii volcanoes) 1  Mauna Loa – This active shield volcano is the second tallest volcano in the world, but it’s the biggest volcano in the world, with the most volume. 2  Hualalai – The third most active volcano in Hawaii. 3  Kilauea – An active volcano on the eastern side of the Island of Hawaii.