In 1584, Baltasar de Obregón described the people he met in the Casas Grandes Valley (CGV), Northwest Chihuahua, Mexico. He juxtaposed these “rustic” people with the sophistication of the ancient builders of Paquimé who had lived in the CGV. Seventy years later, the Spanish missionaries called the people in the CGV “Suma” and enlisted them to build Mission San Antonio de Padua de Casas Grandes. Scholars have examined Obregón's and later administrators’ accounts to argue that the Suma were a small-scale society and unrelated to the ancient people of Paquimé (~AD 1200–1430). We reevaluate this interpretation. First, we contextualize the documentary evidence within contemporary frameworks. Second, using data from the 1958–1961 Joint Casas Grandes Expedition, we compare Paquimé and Suma material culture. We argue that the Suma were likely long-term residents of the Valley, organized into horticulture villages, and exhibiting cultural practices linked to Paquimé. After critiquing previous arguments about Suma origins, we consider how this criticism relates broadly to exploring Native Americans’ reactions to colonial settings.