Book excerpt: Introduction -- The why of transnational familial formations -- Growing up transnational: Mexican teenage girls and their transnational familial arrangements -- Muchachas Michoacanas: portraits of adolescent girls in a migratory town -- Migration marks: time, waiting, and desires for migration -- The telling moment: pre-crossings of Mexican teenage girls and their journeys to the border -- Imaginaries and realities: encountering the Napa Valley -- Conclusion