the theory of the metabolic rift offers historians and ecologists alike a new means of exploring the relationship between humans, nature, and capital. based on the works of karl marx, the theory of the metabolic rift argues that environmental degradation in the twentieth-century corresponds with the growth and intensification of industrial capitalism. marx attributed capitalism’s ecological damage to the inabilities of industry to maintain its metabolic rate with nature. what develops are what marx calls “irreparable rifts” to both humans and nature. increased appropriable land, new technologies, and new forms of appropriating crisis into new modes of production are the sole means in which the capitalist system can overcome these rifts. while such techniques mend the metabolic rifts of industry, they often make new rifts in other sections of the capitalist substructure. what develops is a series of rifts and shifts which continuously shape the social, economic, and environmental relations between humans, nature, and capital. the social and economic rifts are most apparent through the unequal exchange of energy, capital, and resources between the hinterland and the metropolis. in the metropolis’ pursuit for greater wealth, it takes control of the hinterland’s vast resources and redistributes its energies towards the metropolis. when metabolic rifts occur, they are most often felt in the hinterland, as the metropolis attempts to maintain social, economic, and environmental degradation to the periphery. these rifts are not only a component to developing the resource-based economies of the hinterland but are imperative to maintaining the hinterland-metropolis relationship which has solidified the canadian experience. by analyzing the creation of hepco/ontario hydro through the marxist theory of the metabolic rift, it is evident that the crown corporation established the province’s power grid on an unequal exchange of resources, capital, and energy between the northern ontario and southern ontario. as new economic and environmental rifts challenged the metabolic rate of hepco/ontario hydro’s power grid, the commission adapted to mend the metabolic rifts of its monopoly. hepco/ontario hydro’s transition from hydro-electric power to nuclear power signified the finite limitations of the natural world, and reflected the abilities of capital and technology to mend the environmental rifts of the utilities industry. not only does the history of hepco/ontario hydro demonstrate the rifts and shifts of twentieth-century industrialization, but it exemplifies the social, economic, and environmental challenges to development in northern ontario.