Pat Abbott call a plug dome volcano. What’s unusual is that hikers are able to see the exposed volcanic plug with its columns. "Where you see all those hexagonal columns," Abbott said ...

Four types of volcanoes—shield, composite, cinder cone, and plug dome—can be found in Lassen Volcanic National Park, where they literally bubble and steam.

Pat Abbott call a plug dome volcano. What’s unusual is that hikers are able to see the exposed volcanic plug with its columns. "Where you see all those hexagonal columns," Abbott said ...

The park is home to more than 40 volcanoes, bubbling mudpots, steaming fumaroles, stunning mountain views and vast, naturally dark skies. The park's namesake peak is the one of the largest plug dome ...