Understanding the complex relationships among social identities, long-distance exchange, and migration has long been an important issue in archaeology. In the central Andes, archaeologists have grappled with these issues to understand highland–coastal interaction. We present a case study of these relationships in the coca-growing zone of the Moche Valley (chaupiyunga zone, 200–1,200 m asl) during the Early Intermediate period (400 BC–AD 600). We focus on reconstructing the social identities of the people who lived at Cerro León, a large hill town situated astride an important access route into the chaupiyunga from the highlands. Unlike most sites in the chaupiyunga, the site is dominated by highland-style pottery. Petrographic analysis indicates that the sources of the highland-style pottery were in the adjacent highlands. Our analysis of daily domestic activities, vernacular architecture, personal adornment, and ritual practices, including burial practices, indicates that most of the residents of Cerro León were immigrants from the highlands. We argue that these immigrants produced and reproduced a distinctive highland (Culle) identity throughout the occupation of the site, which lasted 100 to 200 years. Evidence demonstrates that site residents had extensive exchange relationships with coastal Yunga communities in the lower and middle Moche Valley.