The harrowing photo of a drowned toddler and her father along the Rio Grande has illustrated the risks migrants are willing to take to reach the U.S., even as increasingly hard-line policies by President Donald Trump’s administration aim to keep them out.

For many people trying to enter the country, it’s a matter of waiting, waiting and waiting some more for the OK to come across, unless they try to force the issue and slip over the border, a dangerous and sometimes lethal undertaking that involves trekking through the scorching desert and fording the deceptively tricky Rio Grande.