Prolific use of crime mapping has led to critical inquiry as to the power and impact of mapping on criminology, public policy, and understandings of crime and violence more generally. Despite the proliferation of maps, few critical inquiries into the power of crime maps exist. Drawing on the historical emergence of crime mapping in one urban juvenile court, this article shows how maps hid and obscured existing power relations based on race and class. Instead of undoing the power of scientific racism in the juvenile court, the emergence of mapping rationalized and normalized the imagined geography of delinquency contained within eugenic philosophies of delinquency. These two eras are joined by a single epistemological cartography of delinquency that continues to pervade the court.