The 1966 law created a process known as Section 106, requiring federal agencies to consult with states, tribes and other stakeholders before projects that could harm historic resources move forward. More than 100,000 properties are listed on the National Register of Historic Places, from individual buildings to broader sites and districts.

The process does not automatically block construction. It is meant to identify potential harm and consider ways to avoid or reduce it. The National Trust for Historic Preservation says reviews take an average of 16 days nationwide and that 98% find no adverse effect on nearby historic resources.

A federal council whose 24 members include 20 appointed by President Donald Trump voted this summer to revise Section 106 regulations. The proposed changes would narrow which properties qualify for consideration, make public comment optional and remove a requirement to consult with Native American tribes. The revisions are still in the rulemaking process; a 30-day public comment period has not yet opened. The council is scheduled to meet Nov. 10.

A separate measure could make changes through federal law. A bipartisan group of senators introduced the American Affordability and Jobs Act in late September, describing it as a way to reform permitting and environmental review to support cheaper energy, jobs and growth. The bill would also narrow aspects of Section 106 review, according to preservation advocates, by limiting public and tribal input, reducing the scope of analysis and restricting legal remedies. The Senate plans to consider the measure after returning from recess Nov. 9.

Supporters of preservation say the two efforts could leave communities with less say over federally backed projects and put historic and archaeological sites at greater risk. Brent Leggs, president and CEO of the National Trust, said historic preservation has depended on public and private partnerships, and argued that the federal government has reduced its role in that work.

Valerie Grussing, a legislative affairs and partnerships executive with the National Association of Tribal Historic Preservation Officers, said the proposed changes would reverse progress made in giving tribal communities a role in preservation decisions. Tribal organizations and other groups recently urged Senate leaders to remove the bill’s Section 106 provisions and develop a replacement in consultation with tribes and preservation groups.

The law grew out of concern over widespread damage to historic places during postwar urban renewal and highway construction. By 1965, half of 12,000 buildings documented in a federal survey had been destroyed or damaged beyond repair. The demolition of New York City’s original Penn Station became a prominent example of the losses that helped spur the preservation movement.

Congress expanded the law in 1992 to include Native American tribes and Native Hawaiian organizations in preservation responsibilities. Tribal leaders say that role is now at risk. Ira Matt, executive director of the tribal preservation officers’ association and a member of the Salish Tribe, warned that statutory changes could remain in place long after current officials leave office.

The senators backing the permitting bill say it would accelerate infrastructure and energy projects. Critics, including attorney Greg Werkheiser, counter that excluding consultation early could create more disputes and litigation later. Werkheiser also said the bill leaves key terms undefined, which could shift disagreements over how the law works to the courts.

Section 106 has helped prevent demolitions and development on archaeological sites, though experts say its value also lies in documenting places that cannot be saved. The National Trust has launched a legal defense fund with an initial $10 million fundraising goal as preservation groups organize against the proposed changes.

The stakes extend beyond nationally recognized landmarks, advocates say: Section 106 can give residents and tribal governments a voice when federal projects affect places tied to local history, culture and community life.