Archaeologist Nels C. Nelson was active during much of the first half of the twentieth century. His career began in the heyday of ìmuseum anthropologyî and ended just at the dawn of the processual era. Typically acting on behalf of more senior figures, such as Alfred Kroeber and Clark Wissler, he had a deep personal involvement in the culture of American archaeology at a time of transition. The complex politics and personalities that shaped regional institutions, as well as Nelsonís own circumstances, are particularly well-documented in associated archival materials. This paper discusses these themes in the context of Nelsonís fieldwork in Southern California between 1908 and 1912, with reference to the longer arc of his engagement with the profession.