The National Park Service (NPS) has released an assessment concluding that President Trump’s proposed Triumphal Arch would have adverse effects on historic sites and views across Washington, D.C. After the NPS reopened public comment for its review and solicited input from outside groups, it compiled a list of nearly 40 locations. The assessment identifies 37 historic sites at risk for adverse impacts, using the federal standard of “adverse effects,” which in this context refers to harms that would reduce or permanently change the experience, views, or historic character of surrounding places.

One area highlighted as most affected is the Memorial Avenue Corridor between the Lincoln Memorial and Arlington National Cemetery, including Arlington House and the Kennedy gravesite. The assessment says a planned 250-foot arch would alter or obstruct sightlines from multiple sites within the corridor, which is described as a major element of the city’s monumental core.

Both reports describe the NPS review as part of a Section 106 process under the National Historic Preservation Act. The assessment is intended to prompt agencies to consult, consider alternatives, and evaluate design changes before any final construction decision, though it does not require that the project be altered or stopped.