This footage was filmed and produced 11 September 2023.

Fewer people are crossing from Mexico this year compared to last year, but there have been more than 500 deaths in 2023-confirmed by the discovery of bodies or partial remains by Don White of the Brooks County Sheriff's Office and others like him. In 2022, one of the deadliest in recent years, there were 853 confirmed deaths.

The Border Patrol has been posting warnings on social media.

"Extreme temperatures contributed to 45 people being rescued and 10 people dying due to the heat and dangerous conditions," Jason Owens, the agency's director, wrote in July on X, formerly known as Twitter. He said his agents had found 13 dead migrants the previous week.

Even migrants who make it across the river and inland face myriad challenges, White said. Guided by smugglers, many migrants take risky routes to avoid a Border Patrol checkpoint at Falfurrias, about 80 miles north of the Rio Grande, often without enough food or water to endure the daylong journey.

The southwest border of the United States has become known as one of the deadliest in the world. Since 1998, at least 7,805 people have died trying to cross the border into Mexico and more than 3,527 are still missing, reports the Colibri Center for Human Rights, an advocacy organization that reports on missing migrants and conducts DNA searches to identify remains.

This video illustrates various shots of migrants crossing the Sonora-Arizona border.