The Loomis Museum at Manzanita Lake offers information, exhibits, videos, Ranger-Led programs and publications in the summer months.

B.F. Loomis documented Lassen Peak's most recent eruption cycle and promoted the park's establishment. He photographed the eruptions, explored geologically, and developed an extensive museum collection. Artifacts and photographs of the 1914-1915 eruption are on display in the Loomis Museum. New exhibits feature the original equipment Loomis used to photograph the eruptions and traditional Atsugewi basketry