Photograph from the National Geographic expedition to the Valley of Ten Thousand Smokes in 1917.
After a massive volcanic eruption at Novarupta in 1912, National Geographic funded several expeditions to the Katmai region from 1915 to 1919. Pictured: Explorers cook dinner over a fumarole, or vent, 1917.
Members of the National Geographic expedition in 1917 use geothermal heat from the fumarole to cook their food. Caption reads: "Fishing the pot out of the cookstove in a contrary wind."
Members of the National Geographic expedition party exploring the Valley of Ten Thousand Smokes in 1917.
Photograph from the National Geographic expedition to the Valley of Ten Thousand Smokes in 1917.
The village of Kodiak, Alaska, in 1916, is the departure point for the National Geographic expedition headed to Katmai.
Two explorers attempt to forge the Katmai River in powerful currents, 1916.
Photograph by explorer Robert F. Griggs from a National Geographic expedition to the Valley of Ten Thousand Smokes, 1917.
Photograph by explorer Robert F. Griggs from a National Geographic expedition to the Valley of Ten Thousand Smokes, 1917.
Photograph by explorer Robert F. Griggs in 1917. Caption reads: "Taking the temperature of a hot one. Our thermometer read only to 360 centigrade. Not that the steam does not condense for some distance from the vent."
Photograph by explorer Robert F. Griggs of the party's camp on Baked Mountain, Valley of Ten Thousand Smokes, 1919.
Photograph by explorer Robert F. Griggs from a National Geographic expedition to the Valley of Ten Thousand Smokes, 1919.
Photograph by explorer Robert Griggs from a National Geographic expedition to the Valley of Ten Thousand Smokes, 1915-1919.
A member of the 1919 National Geographic expedition collects water from a snow melt. Caption reads: "Our drinking pool at the margin of the snow drift."
Heat from the ground melts tunnels through ash-covered snowdrifts, on the 1919 Nat Geo expedition to the Valley of Ten Thousand Smokes.
Group portrait of the 1919 National Geographic expedition before sailing to Katmai: (left to right) Helt, Sayre, Hagelbarger, Kolb, Yori, Griggs, Folsom, Fenner, Allen, Miller, Zies, Hine, Wallace, Basinger, Stone, Henning.
Chemists prepare to collect gas from a fumarole in the Valley of Ten Thousand Smokes, 1919.
Explorers sort through their camp's wreckage after a storm in the Valley of Ten Thousand Smokes, 1919.
Photograph from a National Geographic expedition to the Valley of Ten Thousand Smokes, 1917.
An explorer holds up a large piece of pumice that was created by the 1912 volcanic eruption. Caption reads "A chunck [sic] of pumice so light it will float on water."
In 1912, the Katmai Valley was buried in one of the largest volcanic eruptions of the 20th century. Nat Geo explorer Robert F. Griggs was among the first to survey the aftermath, and gave the area its name: "Valley of the Ten Thousand Smokes."
Novarupta was the largest volcanic eruption by volume of the century. Its ash cloud rose to an elevation of 20 miles, and the sound of its blast could be heard 750 miles away. The resulting Valley of Ten Thousand Smokes is now a national landmark.