The U.S. has seen a historic number of illegal border crossings this summer — a 21-year high, according to federal figures. Why is this happening? One reason: Thousands of migrants are waiting in northern Mexico — some for months — to claim asylum in the U.S. because President Biden extended a Trump-era pandemic policy that effectively bars them from entering the country.In Mexico, the migrants — many from Central America — are at risk of being kidnapped, extorted or killed by smugglers. Yet more decide to make the dangerous journey to the border every day, seeking refuge in the U.S.41-year-old El Salvador native Rosario Yanira Girón de Orellana was one of them. Her body was found on a ranch in Texas in June. This is her story.More reading:Losing Rosario: A mother sent her daughter across the border. Before they could reunite, one diedLa muerte de Rosario: Una madre envió a su hija al otro lado de la frontera. Ella falleció antes de que pudieran reunirseWhy Border Patrol is doing more to rescue and identify missing migrants