Starting in the 1950s, the Rocky Flats Plant in Golden, Colorado, produced every plutonium trigger for U.S.-made nuclear warheads. But a 1989 raid by the FBI put a stop to the site’s nuclear production, its operators later pleading guilty to criminal violations of environmental law. Five years later, Rocky Flats sat unused and badly contaminated. The Department of Energy (DOE) called the site “one of the country’s most significant nuclear vulnerabilities,” projecting that cleanup would take 70 years and cost $36 billion. This case study tells the story of how the Department of Energy, Kaiser-Hill Co., the Rocky Flats Coalition of Local Governments, and a non-profit Citizens Advisory Board, which included community, activist, and government representatives, worked together to clean the site more than 50 years ahead of projections and ensure that the effort met not only federal regulations but also the needs of the community. Since 2007, the former nuclear weapons plant has been managed by the U.S. Fish & Wildlife Service as a National Wildlife Refuge, home to herds of mule deer and elk, along with the threatened Preble’s Meadow Jumping Mouse.