Images

Mount Konocti, a mostly dacitic composite cone, on the western shore of Clear Lake, California. Thurston Lake is in the foreground.

Apollo 16 astronauts John Young (right) and Charlie Duke (left) ride in Earth-adapted Lunar Roving Vehicle "Grover" in the Coso Volcanic Field near Ridgecrest California, November 1971. Photo by NASA.

University of Texas professor William R. Muelhberger (left foreground) with Apollo 16 commander John W. Young (right foreground), astronaut Charles Duke (center), geologist David Wones (second left), and astronaut Anthony England on an Apollo 16 geology field trip to Mono Craters in June 1971. Photo by NASA.

View of Donald A. Beattie (manager of NASA's lunar surface experiments) during a geological field trip to the Medicine Lake Volcano, California in September 1965. Beattie was joined by astronauts William Anders (Apollo 8), Alan Bean (Apollo 12), and Rusty Schweikert (Apollo 9). Photo by NASA.

The original Lassen Volcano Observatory building, provided by the US Forest Service, about 1926. The observatory consisted of a small office over a 10x10 ft concrete cellar which housed two custom-built seismographs. A small cottage nearby housed Ruy H. Finch, the head of and sole scientist at the Observatory for much of its existence. (Photo by R.H.

The founder of the Lassen Volcano Observatory (1926-1935) and second Director of the Hawaiian Volcano Observatory (1940-1951), Ruy Herbert Finch conducted research in both Hawaii and throughout the Western United States.

Coso Hot Springs in Coso volanic fields, Feb 4, 1920.

Lassen Peak photographed from the Devastated Area about 4 hours before the explosive eruption of May 22, 1915.

Benjamin F. Loomis Historical Photograph Collection: Lassen Peak showing new lava flow on summit and large mudflows on slopes. Photo courtesy of NPS.

A second view of Lassen Peak and the Deveastated Area following an explosive eruption and mudflowk. The crater of the volcano is visible, revealing that a lava dome which had previously been growing there was destroyed by the explosion. Subsequently, a lava flow began refilling the crater, and was mistakenly thought to have created the mudflow. 

Benjamin F. Loomis Historical Photograph Collection: Lost Creek drainage area covered in mud, rocks, and debris from a mudflow off Lassen Peak. Photo courtesy of NPS.

Steam issuing from summit of Lassen Peak from head of Lost Creek following mudflow. "Hot Rock"(large boulder) in foreground. Photographs taken a few hours prior to second major eruption and hot blast.

Lassen Peak photographed from the Devastated Area prior to the 1914-1915 eruption that changed the landscape.

Photograph of men at the Kelseyville Gas Wells, ca.1910, by M. Rieder. Courtesy of California Historical Society Collection, University of Southern California Digital Libraries. 

Horse-drawn carriage on road in Sisson, California, El Monte Hotel in foreground, Mount Shasta in the background. Image courtesy of the Library of Congress.

Photograph of the town of Sisson (later (1922) the town of Mt. Shasta) in the distance at the foot of Mount Shasta in winter. Snow covered fir trees in the foreground. Photo courtesy of University of Southern California Libraries and California Historical Society. Digitally reproduced by the USC Digital Library.

Infographic about the 2019 report "California's Exposure to Volcanic Hazards"

In a February 5, 2019 visit, USGS Director Jim Reilly was given a tour of CalVO facilities, including the Operations Room. Here Emily Montgomery-Brown explains the networks that monitor California's threatening volcanoes.