In Bumpass Hell, and active volcanic area is one of the classic Lassen Volcanic NP hikes, sulfer emissions stain the landscape. Lassen Peak, one of the worlds largest plug dome volcanoes, last erupted in May, 1914. Called a miniature Yellowstone by many, mud pots, fumaroles and boiling water continue to this day. Lassen is part of the Pacific Ring of Fire. This view from Highway 89, which traverses the park, looks east toward Juniper Lake and Snag Lake.