Book excerpt: Around 400 BCE, inhabitants of the Southern Andes took up a sedentary lifestyle that included the practice of agriculture. Settlements were generally solitary or clustered structures with walled agricultural fields and animal corrals, and the first small villages appeared in some regions. Surprisingly, people were also producing and circulating exotic goods: polychrome ceramics, copper and gold ornaments, bronze bracelets and bells. To investigate the apparent contradiction between a lack of social complexity and the broad circulation of elaborated goods, archaeologist Joan Gero co-directed a binational project to excavate the site of Yutopian, an unusually well-preserved Early Formative village in the mountains of Northwest Argentina. In Yutopian, Gero describes how archaeologists from the United States and Argentina worked with local residents to uncover the lifeways of the earliest sedentary people of the region. Gero foregounds many experiential aspects of archaeological fieldwork that are usually omitted in the archaeological literature: the tedious labor and constraints of time and personnel, the emotional landscape, the intimate ethnographic settings and Andean people, the socio-politics, the difficult decisions and, especially, the role that ambiguity plays in determining archaeological meanings. Gero's unique approach offers a new model for the site report as she masterfully demonstrates how the decisions made in conducting any scientific undertaking play a fundamental role in shaping the knowledge produced in that project.