Figure 3. View of King's Bowl and Great Rift.

Native Americans have visited the area of Craters of the Moon National Monument for thousands of years. They were potential witnesses to at least the last 3 eruptive periods of the COM lava field and for the formation of both the Wapi and Kings Bowl lava fields. Scientific studies began in 1901, when Israel Russell, United States Geological Survey (USGS), came to investigate south-central Idaho. Russell wrote the first scientific account of the region called "Cinder Buttes" (Russell, 1902). His intense interest in the volcanic bombs that he discovered brought him back again the following year (Russell, 1903). Starting in 1910, S.A. Paisley, who later became the first Custodian of the Monument made numerous trips into the area and Era Martin, a local resident, discovered and marked many of the caves and water holes with stone monuments (Stearns, 1928).

In 1921, Robert Limbert, a taxidermist from Boise, Idaho, visited the area and published an account of his trip in National Geographic (Limbert, 1924). In the same year, O. Meinzer, Chief of USGS Division of Ground Water, and Harold Stearns, USGS, visited the area. In 1923 Stearns, accompanied by F.E. Wright of the Carnegie Institution made a trip to the area and published a description in Geographical Review (Stearns, 1924). The National Park Service (NPS) requested Stearns to submit a report describing the area, delineating boundaries, and stating the reasons that would justify its preservation as a National Monument and on May 2, 1924 President Calvin Coolidge proclaimed the original Craters of the Moon National Monument. In 1925, the first topographic map of the Monument was made by M.J. Gleissner, USGS (Stearns, 1928). In the fall of 1926, Stearns again returned to the Monument and spent a month mapping the geology and describing the features. He submitted a report to the USGS, but only portions of it were published (Stearns, 1928; Stearns, et al, 1938). The 1938 publication contained the first generalized geologic map of the monument.

Since these early geologic investigations, numerous additional studies have been conducted to workout the regional geology and structural setting, the source of the volcanism, the petrology and mineralogy of the lavas and underlying rocks, and the chronology of the lava flows. The 1950's and 60's produced many reports speculating on the structure of the western Snake River Plain (Malde, 1959; Malde and Powers, 1962, Malde, et al, 1963; Hill, 1963). In the 1970's detailed petrologic and geochronologic studies were initiated and research began on the geochemistry of the basalts and underlying rhyolites of the plain. Simultaneously, dating began using both radiocarbon and K-Ar (potassium-argon) techniques to determine the absolute age of the lava flows. Mineralogical studies at this time focused on the Blue Dragon flow in the Monument and on the unusual mineral deposits found in some of the lava tubes and pits (e.g.: Armstrong, et al, 1975; Bullard, 1970; Faye and Miller, 1973; Malde and Cox, 1971, Peck, 1974). Christiansen and McKee (1978) published the first report of a mantle plume theory for the formation of the Snake River Plain. From the 1980's to the present geologists concentrated on refining the petrologic characterization and absolute dating of the rocks and on magmatic and eruptive models to explain the regional volcanism. Kuntz, et al, (1982) dated lava flows within the monument and (Kuntz, et al, 1986) provided significant information regarding the source, volume and periodicity of the basaltic eruptions. Smith and Braile (1993) described the space-time evolution of the Yellowstone-Snake River Plain volcanic system. Geophysical techniques, such as tomography (imaging based on P-Wave velocity structure), were used to determine the subsurface geology of the plain (Humphreys, et al, 2000).