Wildflowers bloom in Tuolumne Meadows at Yosemite National Park. An influx of nitrogen-based pollution is acting as an unwanted fertilizer and is disrupting the ecology of dozens of national parks ...

Data collected by the National Park Service show parks failed to meet U.S. air quality standards for ozone at least 85 times this year. In 2016, national parks exceeded the standard a combined 276 ...

Pollution wafting up from lower elevations threatens to spoil beloved national park’s pristine beauty Chasm Lake sits 2,500 feet below the dramatic summit of Longs Peak in Rocky Mountain ...

The programs, which operated at all 63 national parks, monitored air quality and collected data regarding the pollution levels to limit health risks in the parks and protect the wildlife.

The park and all 47 other national parks in the U.S. are plagued by significant air pollution problems, according to a recent analysis from the National Parks Conservation Association, that harm ...

At Sequoia National Park, about 200 miles (322 kilometers) north of Los Angeles, there have been more bad ozone days than in the city in all but two years since 1996, the study said.

Battling pollution at the Great Smoky Mountains National Park. The Great Smoky Mountains National Park bordering North Carolina and Tennessee is not only a natural paradise but also is home to ...

A new national report on the health of the nation’s national parks found that 96 percent of are plagued by significant air pollution problems. In Rocky Mountains National Park, pollution issues ...

Harmful nitrogen pollution is still drifting onto fragile, high-elevation ecosystems in Rocky Mountain National Park from Colorado highways, power plants and livestock operations, state and federal… ...

During the June-to-September summer season last year, the park violated the National Ambient Air Quality standard at least 87 times, compared with 56 at Joshua Tree and 12 at Great Smoky Mountains.

The famed redwoods of Sequoia National Park are slowly yet surely being replaced by another kind of enduring landmark: a sky-spanning carpet of lung-blistering smog. Wafting in on an eddy that ...