Despite five decades of experience, there is a considerable gap in legal and empirical study on the impacts of the National Environmental Policy Act (NEPA). Proponents of reform often claim NEPA litigation is a major obstacle for federal actions; others have concluded litigation is not a major contributor of project cost escalation or delays. This Article studies the incidence and conditions of infrastructure project litigation under NEPA, using a data set of 355 major transportation and energy infrastructure projects that completed a federal environmental study between 2010 and 2018. We observe predevelopment litigation on 28% of the projects requiring an environmental impact statement, 89% of which involve a claim of a NEPA violation. The highest litigation rate is in solar energy projects, nearly two-thirds of which are litigated. Other high-litigation sectors include pipelines (50%), transmission lines (31%), and wind energy projects (38%). Energy sectors with greater private financing have shorter permit durations and higher rates of litigation and cancellation, but also higher completion rates relative to transport sectors, which have greater public financing and lower litigation rates but longer permit timelines.