For more than a century, clandestine migrants have traveled over the U.S.-Mexico border. Beginning in 1882, the U.S. Congress passed its first legislation to restrict migration, which led some banned migrants to enter the United States through clandestine pathways as the earliest unauthorized migrants. Over the following decades, Congress passed additional legislation and increased enforcement efforts to deter migration across the border. However, despite the focus on reducing unauthorized migration, clandestine migrants have continued to transit through South Texas. This report focuses exclusively on these clandestine migrants, who seek to avoid detection as they cross through the region’s borderlands.

In particular, this policy research report addresses three questions related to clandestine migration. These questions are: 1) How do clandestine migrants transit through this region? 2) What are the risks to migrants during their journeys? and 3) Who are the individuals that facilitate clandestine migration in South Texas? To answer these questions, we used a mixed methods approach. We relied on two original datasets—the Smuggling Incident dataset and the Migrant Testimony dataset—that examine the different migration phases and the demographics of individuals facilitating clandestine migration. Additionally, for migrant deaths, we used a Border Patrol dataset and county-level datasets from Brooks County, Kenedy County, and Maverick County. To fill in any research gaps, we conducted interviews with federal and local officials, law enforcement, and journalists.