In January 2012, I traveled to Oklahoma City for the first time to report on what was considered a surprising development: a U.S. oil boom. Until then, hydraulic fracturing—aka fracking—was best known for boosting U.S. natural gas production. It was just starting to be used to unlock oil trapped in deep underground layers of rock like the Bakken Shale in North Dakota, the Eagle Ford in Texas, and the Mississippi Lime in Oklahoma. Still folded in my notebook is a typed list given to me that week by Gene Pflughoft, then the executive director of Central Oklahoma Regional Development. It enumerated the benefits of tapping shale: “Leasing the land, drilling rigs, built with hundreds of components, thousands of employees; trucks to deliver drilling rigs; drilling: many employees, highly skilled; training facilities, teachers, cooks, coordinators, janitors. […]