A large literature in health economics seeks to understand the impact of geographic proximity to healthcare providers on health outcomes. This literature typically exploits hospital closures. Instead, I use highway network expansions, which reduce travel time to the hospital, to examine the impact of geographic proximity to a hospital on heart attack mortality. Preliminary findings suggest only modest improvements in survival for the average patient. The effects are concentrated in patients living in the most remote areas, which experienced the largest reductions in travel times.