If the government can't protect you on the border . . .
Mr McCaslin's small mine sits on a knoll of red earth and scrub near the Mexican border. Like his 19th-century predecessors, he is sure there is money in "them thar hills" after a geological survey indicated there may be rich veins of silver.
Today, however, he has other priorities. For the mine also sits in the middle of a network of trails used by heavily-armed Mexican trafficking gangs to smuggle people and drugs into America.
Notoriously porous, the border has reached new levels of lawlessness this year as smugglers, known as "coyotes", have become increasingly brazen, willing to fire on anyone - from border patrols to the likes of Mr McCaslin - who gets in their way. . . .