The early 1960s are remembered for the emergence of new radical movements influenced by the Cuban Revolution. One such protest movement rose in the Mexican state of Chihuahua. With large timber companies moving in on the forested sierra highlands, campesinos and rancheros did not sit by as their lands and livelihoods were threatened. Continuing a long history of agrarian movements and local traditions of armed self-defense, they organized and demanded agrarian rights. Thousands of students joined the campesino protests in long-distance marches, land invasions, and direct actions that transcended political parties and marked the participants' emergence as political subjects. The Popular Guerrilla Group (GPG) took shape from sporadic armed conflicts in the sierra. Early victories in the field encouraged the GPG to pursue more ambitious targets, and on September 23, 1965, armed farmers, agricultural workers, students, and teachers attacked an army base in Madera, Chihuahua. This bold move had deadly consequences. With a sympathetic yet critical eye, historian Elizabeth Henson argues that the assault undermined and divided the movement that had been its crucible, sacrificing the most militant, audacious, and serious of a generation at a time when such sacrifices were more frequently observed. Henson shows how local history merged with national tensions over one-party rule, the unrealized promises of the Mexican Revolution, and international ideologies.