Previous Work
The earliest documented contact by Europeans with the study area was made by Lieutenant Joseph G. Ives in 1858 as a part of the survey made by the Corps 'of Topographical Engineers on the navigability of the Colorado River. Ives' vessel, the Explorer, passed El Dorado Canyon, but was damaged in Black Canyon. Ives, himself, went further upstream to about the vicinity of Fortification Hill. The incident wherein the boat was damaged may have had some effect on Ives for later in his report he said, "The region last explored is, of course, altogether valueless. It can be approached only from the south, and after entering it there is nothing to do but leave * * *."
Ives expedition - 1858
It is possible that J. S. Newberry, a geologist and member of Ives' party, made the first mineral collections in the El Dorado-Searchlight area. Newberry and others made a short trip up a side canyon of the Colorado to the west (El Dorado Canyon?) during the period when the vessel was being repaired. While there, they gathered samples of what was thought to be opal. Comments on the material are included in Ives' report.
Wheeler survey 1871 - T.H. O'Sullivan photo
G. K. Gilbert described a visit he made to El Dorado Canyon in 1871 for the Wheeler topographic survey. His work is included in the map shown as Figure 1.
The preceding reference to Gilbert was also included in the U.S.G.S. Bulletin 208 by Spurr (1903). This report consolidated much of the earlier work, and included new material on the geology of parts of Nevada and California south of the 40th parallel.
Ransome (1907) described the El Dorado-Searchlight district in his reconnaissance of Nevada s'outh of Goldfield. This report was the initial professional description of the geology of the study area. Although limited in depth and handicapped by a shortage of field work, the report recognized the major features of the structural geology of the district. Vandenburg (1937) is particularly useful for the production figures and extent of workings listed for individual mines. The description of mill processes is unique and valuable.
A word should be inserted here to 'outline what works of a purely historical nature were consulted and made a contribution. The lack of primary sources on the immediate area required substantial use of references from works of larger scope that included fragmentary information. This is particularly true of the period prior to 1897. No local source of social history existed prior to the publication of the Searchlight Bulletin in 1902. Descriptive material concerning 19th century mining activities is primarily in the form of remembrances published by later histories or as human interest stories in local newspapers. With time, these have become altered, and must be considered somewhat suspect until verified. The definitive work 'on the Searchlight District is Callaghan (1941). Each of the major mines, and several of the peripheral camps, is examined in detail. Full production figures and line drawings of the underground workings are provided. A section on the history of the camp is dependable largely due to Searchlight's discovery relatively late in the time-spectrum of western mining.
Hansen (1962) is a recent and valuable dissertation on the geology of the El Dorado Canyon region. It does not cover all the area, but is quite detailed and competently describes the geology of the district.
