Lassen Volcanic National Park: Where the Ground Is Still Working. Lassen Volcanic National Park sits at the intersection of four volcanic systems and is one of the few places on Earth where all major volcano types exist together. With recent eruptions, boiling springs, and steaming vents, the park shows that geological change is still actively unfolding. #nationalpark #hiddenhistory #parkhistory #lassenvolcanic #americanhistory national park history, hidden history, American history, documented