Dual enrollment (DE)--where students earn college credits during high school--is expanding rapidly. To facilitate DE, institutional actors across K-12 schools and colleges must build or repurpose structures across separate organizations to determine course offerings, assignments, modality, and composition. Yet the organization and implications of those structures remain a black box. Using statewide administrative data from Texas, we describe DE coursetaking and course characteristics for traditional Texas public high school students and examine how DE course characteristics predict students' course performance and subsequent college enrollment. Our descriptive analyses illuminate striking differences between academic and career and technical education DE, both in students' backgrounds and course structures. Our regression analyses illustrate how several malleable DE course characteristics predict student outcomes.