We examine the impacts of early college high schools, small schools of choice located on college campuses. These schools provide a no-cost opportunity for students to earn college credit--or a 2-year degree--while in high school. Using rich administrative data on multiple cohorts of students and quasiexperimental methods informed by the within-study comparison literature, we estimate program impacts of enrolling in a North Carolina early college in ninth grade on a variety of secondary and postsecondary outcomes. We include all such schools in the state, and we report generally promising findings. Early colleges increase important high school outcomes, boost associate's degree completion, and raise 4-year-college enrollment at less selective public institutions. We also show the differences of these impacts across race, home-district performance, and host site, helping us better understand the implementation and effects of this promising intervention in one state that has brought this school reform model to scale.