The history of California's Basque boardinghouses, or ostatuak, is the subject of this dissertation. To date, scholarly literature on ethnic boardinghouses is minimal and even less has been written on the Basque "hotels" of the American West. As a result, conclusions in this study rely upon interviews, census records, local directories, early maps, and newspapers. The first Basque boardinghouses in the United States appeared in California in the decade following the gold rush and tended to be outposts along travel routes used by Basque miners and sheepmen. As more Basques migrated to the United States, clusters of ostatuak sprang up in communities where Basque colonies had formed, particularly in Los Angeles and San Francisco during the late nineteenth century. In the years between 1890 and 1940, the ostatuak reached their zenith as Basques spread throughout the state and took their boardinghouses with them. This study outlines the earliest appearances of the Basque ostatuak, charts their expansion, and describes their present state of demise. The role of the ostatuak within Basque-American culture and a description of how they operated is another important aspect of this dissertation. Information from interviews supports the claim that the ostatua was the most important social institution among Americanuak during peak years of Basque immigration. Since a majority of the Basque sojourners who arrived before 1930 were unmarried, unable to speak English, and intended to return to the Old World within a decade of their arrival, the Basque-American often substituted his "hotel" contacts for his Old World family. At the ostatuak, he found a familiar language and cuisine, as well as an employment agency, a place to vacation, translating services, an occasional loan, explanations of his host culture, and new friends from old villages. This history of California's ostatuak is the first of its kind and encourages future research on Basque boardinghouses throughout the American West.