The Mexican Revolution gave rise to the Mexican nation-state as we know it today. Rural revolutionaries took up arms against the Díaz dictatorship in support of agrarian reform, in defense of their political autonomy, or inspired by a nationalist desire to forge a new Mexico. However, in the Gran Nayar, a rugged expanse of mountains and canyons, the story was more complex, as the region’s four Indigenous peoples fought both for and against the revolution and the radical changes it bought to their homeland. To make sense of this complex history, Nathaniel Morris offers the first systematic understanding of the participation of the Náayari, Wixárika, O’dam, and Mexicanero peoples in the Mexican Revolution. They are known for being among the least “assimilated” of all Mexico’s Indigenous peoples. It’s often been assumed that they were stuck up in their mountain homeland—“the Gran Nayar”—with no knowledge of the uprisings, civil wars, military coups, and political upheaval that convulsed the rest of Mexico between 1910 and 1940. Based on extensive archival research and years of fieldwork in the rugged and remote Gran Nayar, Morris shows that the Náayari, Wixárika, O’dam, and Mexicanero peoples were actively involved in the armed phase of the revolution. This participation led to serious clashes between an expansionist, “rationalist” revolutionary state and the highly autonomous communities and heterodox cultural and religious practices of the Gran Nayar’s inhabitants. Morris documents confrontations between practitioners of subsistence agriculture and promoters of capitalist development, between rival Indian generations and political factions, and between opposing visions of the world, of religion, and of daily life. These clashes produced some of the most severe defeats that the government’s state-building programs suffered during the entire revolutionary era, with significant and often counterintuitive consequences both for local people and for the Mexican nation as a whole.