Pre-college advising programs exist in most disadvantaged high schools throughout the United States. These programs supplement traditional advising by high school guidance counselors and attempt to help underrepresented and disadvantaged students overcome the complexities of the postsecondary admission and financial aid processes. Existing evidence on these programs often uses within-school randomization where spillovers and alternative supports may confound estimates. We provide the first evidence on a whole school intervention resulting from a school-level randomized controlled trial in the United States. The college access program we study uses a near-peer model where a recent college graduate works at the school assisting students in the application and enrollment process. Pooled results across the first three years of program implementation find no significant impacts on overall college enrollment. However, subgroup analyses reveal positive, significant effects among the groups most targeted by the intervention: Hispanic and low-income students. Most of the impact comes through increasing two-year college enrollment, but this appears to be new entrants rather than inducing students to move from four-year to two-year colleges. The observed positive effects for these subgroups attenuate over time. We attribute this drop in the estimated impact to departures in fidelity of the experiment. Even among the cohorts for which we find positive enrollment impacts, we find no significant impacts on college persistence. [This article was published in the "Journal of Policy Analysis and Management."]