Americans love national parks. A survey by the National Parks Conservation Association found that two-thirds of the respondents oppose attacks on national parks. So, why is the Trump administration gunning for our national treasures?
The U.S. Environmental Protection Agency (EPA) Administrator Lee Zeldin announced on March 12, 2025, that the federal agency would take 31 deregulatory actions to advance the executive orders President Trump signed on the first day of his second term. Zeldin called that day the “greatest day of deregulation our nation has seen.”
The EPA announced in October 2025 that it would delay the enforcement of regional haze guidelines for national parks and give states a three-year extension to submit cleanup plans. The regional haze program requires states to submit plans outlining pollution reduction strategies every 10 years. The comment period for the new rule ended on December 1, and a second public comment period this year is likely.
Regional Haze Program: Monitoring Air Pollution in National Parks
Federal agencies have monitored air visibility in national parks since 1988, and in 1999, the EPA started the Regional Haze Program for 156 national parks. Under the program, federal agencies work together to improve air visibility.
Air pollution occurs in around 97 percent of national parks. In 2024, 26 parks had at least one day when ozone levels exceeded the healthy level for certain visitors. A 2018 study found that average ozone levels in the parks were almost identical to the levels in the 20 largest U.S. metropolitan areas, and fewer people visit when ozone levels are higher.
However, in May 2025, the Washington Post reported that the Trump administration temporarily suspended air pollution monitoring in national parks. The National Park Service currently has air pollution monitors. Last year, the National Park Service lost $267 million in staff funding.
“Instead of working to protect our environment and the American people from toxic pollutants, Lee Zeldin is instead delaying plans to curb air pollution and letting fossil fuel companies emit more haze into our national parks. The pollutants that have lowered visibility at national parks not only dampen the experience of visiting these crown jewels, but are public health hazards and threaten the well-being of visitors and nearby residents.” Sierra Club Senior Attorney Joshua Smith.
Opposition to Gutting the Regional Haze Rule
Twelve environmental groups sent a letter to the EPA on December 1, 2025, about the Regional Haze rule revisions, urging the EPA to “provide clarity and detailed direction to states in regulatory amendments.” The groups described the revisions as a design “to enable states to evade those requirements,” which violates the Clean Air Act.
The Regional Haze Program has been successful, the groups pointed out in the letter, and has “improved visibility conditions at Class I areas across the country.“ However, the job is not complete because no single Class 1 area “has reached the Act’s goal of achieving natural visibility conditions.”Another letter, sent by 36 groups, urged the EPA to “ensure that any revisions” address the primary goal of reducing visibility in national parks. The groups also urged the agency to require states to make “continued, reasonable progress toward natural visibility in Class I areas.”
Photo by Ganapathy Kumar on Unsplash
