Famed novelist Jack London became America's highest-paid author in 1905, writing about adventures in the Klondike and the Russo-Japanese War and about sailing his self-designed boat halfway around the world. Yet perhaps one of London's finest legacies is his 1,400-acre ranch on the slopes of Sonoma Mountain in California. Sometimes called "Beauty Ranch" or the "Ranch of Good Intentions," the land, buildings, and house museums exemplify both early-20th-century...