Louis Davidson Ricketts (December 19, 1859 – March 4, 1940) was an American economic geologist, metallurgist, mining engineer and banker who pioneered development of copper mines in the U.S. state of Arizona and the Mexican state of Sonora. Early career Ricketts was born in Elkton, Maryland on December 19, 1859. He was educated at Princeton University, earning both a B.Sc. (1881) and D.Sc. (1883), being a Fellow in Chemistry and a Fellow in Economic Geology. He then went to Colorado and began at the bottom in Leadville as mine surveyor and assayer, then foreman of a short-lived mine operation near Silverton, Colorado, and, finally, as a consultant and expert witness on geology for mine lawsuits in Leadville, Aspen and elsewhere. In 1887-1890 he served as Geologist for Wyoming Territory. In 1890 he was recruited by Dr. James Douglas of Phelps Dodge (PD) and began his long mining career in the Southwest borderlands. His first years were filled with more failures than successes. In 1891, Douglas appointed Ricketts manager of the Commercial Mining Company (Phelps Dodge owned) to introduce the Southwest's first Hunt-Douglas process leaching plant at Copper Basin, near Prescott. It burned down, a premature test of hydrometallurgy. The company, backed by Phelps Dodge, also acquired claims adjacent and above the rich United Verde mine at Jerome. Here too Ricketts failed to find profitable ore. Similarly, at Globe, efforts to open several claims for the Phelps Dodge proved marginal. In 1893, he returned to Silverton, Colorado invested in a silver mine, built a mill, and went bankrupt. The failure educated him not to build a costly mill before opening an ore reserve large enough to pay the bills, let alone make a profit. By the mid-1890s, Ricketts was rehired by Douglas and sent to northern Sonora, Mexico, with hopes of finding copper properties. Nacozari, Sonora, Mexico and Morenci, Arizona with PD In 1897, Dr. Ricketts recommended that Phelps Dodge buy the then-small Pilares mine in northern Sonora from the Guggenheim family. Dr. Douglas put him in charge of redeveloping the property, in what became probably the first attempt to mine a porphyry copper deposit by mass methods. As first manager of The Moctezuma Copper Company, Ricketts planned and constructed a modern mine, concentrator, smelter and townsite, connected by railroad. The plant was innovative in that it was constructed of steel frame, and the works powered by electricity. By 1901, when