“Laboratory of Nature: Labor, Land, and the Environment in California’s Imperial Valley, 1940-1999” analyzes a history of how ethnic Mexican farmworkers and their allies in the late twentieth-century contested and negotiated space and power relations in Southern California’s Imperial Valley. This dissertation argues that everyday, working-class people in the Imperial Valley were not passive historical actors in the context of monopolistic, speculative financing on rural lands, but active members of society who contested their surroundings. It examines the intersections between agricultural labor, land disputes, and environmental justice in rural California’s Imperial Valley and concludes with an applied approach to history to help readers recognize contemporary events in ways that may mobilize them through historical perspectives. The dissertation explores social, labor, and environmental histories of southernmost California’s Imperial Valley from 1940 to 1999. It explores the relationship between water projects, ethnic Mexican farmworkers, and community resistance, and it places agricultural history in conversation with environmental, ethnic, and labor studies. Altogether, this dissertation highlights the ways that the Imperial Valley’s environmental conditions are rooted in structures of resource extraction, racialized labor, and industrial capital accumulation. “Laboratory of Nature” demonstrates that industrial farms in the Imperial Valley deployed mechanized agriculture in response to the advances of farmworker unions and the end of the Bracero Program. By honing in on the relationship between agriculture and technology, it shows that the introduction of mechanized farming established new forms of labor control in the fields through the use of machinery that hinged on the grand scale of large-acreage farms. Additionally, it details how agricultural conglomerates in the Imperial Valley conspired with politicians and Bureau of Reclamation officials to circumvent federal reclamation law to control greater access to large swaths of arable land with federally-funded water. Nevertheless, the dissertation highlights the historic contestation and negotiation over rural space between enterprise and everyday people in the Imperial Valley. The final chapter concludes with a streamlined comic book adaptation of the dissertation. The recognition of ethnic Mexican farmworkers in the Imperial Valley during the latter half of the twentieth-century and the ways that they contested people in positions of power go unaccounted for in popular accounts of the region. Apropos of that, this dissertation employs an original oral history project and archival research to illustrate that conventional histories of the Imperial Valley omit a full picture of the region. The dissertation endeavors to provide a more complete history of the region and demonstrates that Southern California’s Imperial Valley is more complex than local histories propose, more violent and oppressive than previously explored, and often steeped in global phenomena in more ways than local histories account for in the written record.