High levels of ozone, found in smog, have injured the foliage of ponderosa pine, Jeffrey pine, and black oak. These basins are major entrances to the parks. The NPS is cooperating with various government agencies in an effort to restore the air quality of the parks, two of America's great natural resources. NPStechnicians have gathered a wealth of knowledge about the causes and effects of smog. Researchers evaluate trees for ozone injury.
Instruments collect rain and sample streams for acidity.
Specialists also are looking at ways to clean up the air in the area. These studies hopefully will inform the public of the dangers and be used to support regional regulations. You can help solve the problem. Walk more both in the parks and at home. Ride a bicycle.