This subseries contains records of William L. Honnold’s business and investment ventures from 1917 through 1930, with the exception of Anglo American Corporation of South Africa, which forms a separate series (Series 5); records of business and investment ventures from 1931 onwards are to be found in Series 4: Chronological files. A significant number of Honnold’s most successful ventures—Calaveras Cement Company, Centrifugal Cast Iron Pipe Company, the Kuhnert Syndicate (from 1929 Pacific Alkali Company), and Noranda Mines—owed their success not simply to Honnold’s considerable business acumen, but also to his mining expertise. However, Honnold also participated in the 1924 founding of Hazeltine Corporation, which specialized in the manufacture of radio equipment and electronic circuits. The profits from Centrifugal Cast Iron Pipe Company, Noranda Mines, and Hazeltine Corporation formed the initial capital of the Honnold Foundation. The Galdyne Corporation and General and Mining Investments Corporation were two closely held Canadian corporations Honnold created in preparation for the creation of the Honnold Foundation. Honnold also invested in real estate in San Francisco (the Montgomery and Sutter Building Company) and San Diego (the San Diego Municipal Warehousing Corporation), as well as in banking in Arizona (the Phoenix National Bank and Phoenix Savings and Trust Bank). The Rio Blanco Ranch Company was formed by Honnold and a few close fishing friends as the holding company for a lodge in Meeker, Colorado, where they all vacationed in the summer (the Honnolds continued to spend at least one month at the lodge until the late 1940s). Many of Honnold’s most successful ventures were carried out in conjunction with various member of the Mudd family and Philip Wiseman, with whom he shared an office at 1206 Pacific Mutual Building, in Los Angeles. Less successful ventures included an automobile financing business Honnold entered into with his former chauffeur and mechanic, Gail Hutchinson (1892-1945), the Baja California Development Company, and, most improbable of all for a man of Honnold’s business acumen, the General Real Estate and Trust Company, a syndicate incorporated in Switzerland in 1921, with the purpose of recovering the estates of the Austrian Archduke Frederick seized by the Austrian republican government after World War I.