DEL RIO, Texas — The remote border town that made headlines last September as tens of thousands of Haitians crossed into it from Mexico has become the top destination for migrants and the epicenter of the border crisis.

Last month, 30,773 people were encountered illegally crossing the border in Border Patrol’s Del Rio sector, which spans 240 miles of the 2,000-mile U.S.-Mexico boundary. For each of the town of Del Rio’s 34,673 residents, one noncitizen was taken into custody.