The Devil's Highway is a journalistic account of illegal immigration from Mexico into the United States. It focuses on the Wellton 26, a group that was attempting to cross the border in May 2001, led by Jesus Antonio Lopez Ramos, an inexperienced young coyote who seemed either ignorant of desert survival techniques or not particularly concerned about the safety of his clients.
They had planned to cross the border and arrive at the town of Ajo, Arizona. Ramos's plan had them walking at night to avoid the heat, something that made it difficult to navigate, especially without appropriate navigational tools such as a contour map, altimeter, and compass. Their route was planned to follow the foothills of the Growler Mountains, as temperatures are lower at high elevations.
The first problem with their plan was that it is very difficult to navigate or walk in the desert at night. Not only are you likely to brush against chollas (a type of cactus with long and very unpleasant spines), but navigation is also quite difficult. You cannot walk in a straight line across the desert, but instead must follow paths along washes or animal trails to avoid the vegetation (most of which has sharp spines); this means following a very indirect course. To avoid getting hopelessly lost, you need good navigational tools. A better choice would be walking in early evening (5 - 8 pm) and the morning (about 4 - 11 am), where you have milder temperatures than midday but still good light. Thus, the first problem they had in navigating was their choice to walk in the dark; they also had to stay off established roads and trails to avoid being caught.
The next problem was that at 11:30 pm they saw lights in the pass which would have led them in the right direction, but, afraid that the lights belonged to the border control, decided to seek another route. They headed northwest, leading them to lower elevations. The next morning, Ramos, probably suffering from heat exhaustion, led them far off course, heading south rather than north.