This paper analyzes how enforcement along the U.S.-Mexican border has affected the market for migrant smugglers. Using a unique dataset that links border crossing histories from illegal Mexican migrants to aggregate enforcement and punishment statistics, we find that the effect of enforcement on smuggling prices is small. Though enforcement has more than tripled over the past fifteen years, smuggling prices have increased by at most 30 percent. Unlike estimates from illegal drugs, the demand for border smugglers is however price elastic. We also show that illegal migrants have switched from heavily patrolled areas to more remote and dangerous crossing routes. These avoidance costs are in fact three times the direct costs of enforcement on smuggling prices.