Out of the thousands of unidentified bodies scattered across the country, many are found in South Texas, where migrants are crossing into the U.S. from Mexico.

Crossing the border is treacherous – it’s hot and there’s a lot of ground to cover. Dehydration and heatstroke claim many who try to make the trek. And dying in Brooks County means that sometimes, their bodies aren’t found, let alone identified.

So what happens to these remains? Host Al Letson and producer Delaney Hall travel to the border to find out, and they interview The Investigative Fund’s John Carlos Frey about what he learned while reporting this story.

Al Letson is a playwright, performer, screenwriter, journalist, and the host of Reveal. Soul-stirring, interdisciplinary work has garnered Letson national recognition and devoted fans.

Delaney Hall is a radio and broadcast producer for Reveal. Hall previously worked with NPR’s "State of the Re:Union," where she produced long-form stories on LGBT Mormons in Salt Lake City; a possible wrongful conviction case in Fairbanks, Alaska; police shootings in Albuquerque, New Mexico; and the legacy of a devastating race riot in Tulsa, Oklahoma. Before that, she co-created the Austin Music Map at KUTX, produced for the Third Coast International Audio Festival in Chicago and reported stories for NPR's "All Things Considered," Latino USA, 99% Invisible and the BBC. She attended the University of Texas, Austin and the Columbia University Graduate School of Journalism. Hall is based in Reveal’s Emeryville, California, office.