By guaranteeing college admission to all students who graduate in the top 10% of their high school class, H.B. 588 replaced an opaque de facto practice of admitting nearly all top 10% graduates with a transparent de jure policy that required public institutions to admit all applicants eligible for the guarantee. The transparency of the new admission regime sent a clear message to students attending high schools that previously sent few students to the University of Texas at Austin and Texas A&M University. Using 18 years of administrative data to examine sending patterns, we find a sizeable decrease in the concentration of flagship enrollees originating from select feeder schools and growing shares of enrollees originating from high schools located in rural areas, small towns, and midsize cities, as well as schools with concentrations of poor and minority students. We also find substantial year-to-year persistence in sending behavior once a campus becomes a sending school, and this persistence increased after the top-10% policy was implemented.