From 1997 to 2018, the US Border Patrol reported 7,505 migrant deaths along the southwestern border. While this figure is mind-bogglingly tragic, the true number is likely much, much higher. — Not many people are searching Arizona’s isolated, scorching desert for the remains of missing migrants, whose families hundreds or thousands of miles away wait with bated breath for news. Finding missing migrants or searching for corpses isn’t in the Border Patrol’s job description, so a volunteer group called the Aguilas…