California has been an oil and gas state throughout its history. In the latter half of 19th Century and first half of the 20th Century, hydrocarbon extraction helped define both Californian prosperity and the early promise of the West. Many decades later, the Energy Act of 2005 helped to revitalize domestic oil and gas production by exempting a suite of new "enhanced recovery techniques" for well stimulation, commonly referred to as "fracking", under major federal environmental regulations. This dissertation research engages the subsoil political ecology of California's petroleum sector in order to explain how well stimulation regulation evolved in California following the rapid deployment of fracking technology across the country that triggered a decade of "Shale Revolution" beginning in 2006. Well stimulation in California represents a case study of the intensely politicized and contested evolution of extractive regimes and their environmental governance at subnational scales in the wake of disruptive technological change. The embedded single-case design employed in this research targets two units of analysis: regulation and frames. Regulation is analyzed using Governance and Political Economy Analysis to assess the structural, institutional, and stakeholder dynamics of California's oil and gas sector, while frames are analyzed using Frame Analysis of news media and semi-structured open-ended interviews to examine how discourse coalitions construct narratives with which to advance their agendas. This dissertation research contributes to the academic literatures relating to energy systems and their sociotechnical transitions by situating the case of well stimulation regulation in California within the substantive, theoretical, and philosophical debates surrounding the environmental governance of extraction.