University of Arizona

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Elgin Bryce Holt Report

Elgin Bryce Holt (1873–1945) was an American mine engineer and owner, geologist, anthropologist, and entrepreneur. Holt reorganized and managed the Cerro de Plata Mining Company in Magdalena, Sonora, Mexico, where he found success in mining silver and was known as "Silver King of Sonora."

The collection contains a three-page typescript report from Holt to his partner, a Mr. Brock, about the Santa Eulalia group of mines near Sombrerete District, state of Zacatecas, Mexico, dated August 11, 1927. Included are four blueprints: an assay map, a geological plan, a surface plan, and a hand-drawn map of important mining camps in the area.