Revisions to the National Historic Preservation Act (NHPA) being proposed at the instigation of the Trump administration would drastically diminish the effectiveness of the act in protecting historic and cultural resources in the US. The changes under review by the Advisory Council on Historic Preservation (ACHP), which is now packed more than half with Trump appointees, oversees the NHPA. The public’s opportunity to comment on federal historic preservation policies or actions would now be entirely optional, at the discretion of the federal agency. These regulations are inconsistent with the National Historic Preservation Act and would violate the Council’s own rules and procedures. The revisions make public comment optional rather than mandatory, narrow the definition of historic property, and shift decision-making authority almost entirely to federal agencies—sidelining state historic preservation officers, tribal historic preservation officers, tribes, and local governments.