The area in Phelan, CA where the hostage scenes take place sits along the Cajon Pass and is known as Mormon Rock, Rock Candy Mountains, Potato Head Mountains, and Hollow Eye Canyon.
Frank Bain: [Frank opens the trunk of his car revealing Jerry inside. He kicks out at Frank, but misses] I'm gonna write that off as you needing to stretch out, but it's out of your system now, right?