When the modern era of environmental policy began with creation of the Environmental Protection Agency and passage of the Clean Air and Clean Water Acts, economists and economics were little used. Over time, economics became a major contributor to formation of environmental policy. Executive Order 12291 pushed economics into the policy process but also rendered benefit-cost analysis controversial. I report on economics’ role in the policy process over time and examine contributions by economists to environmental policymaking. Advancing benefit-cost analysis is an obvious contribution. I describe other areas in which economists have contributed and highlight milestones for economics at EPA.