Where the decibels mount

When the national park system was created at the beginning of the 20th century, few could have foreseen how the often remote and inaccessible slices of wilderness would become surrounded by commercial development, traffic congestion and recreational clamor. While visitors to some parks, such as the Statue of Liberty National Monument in New York Harbor, don’t expect natural quiet, noise has become a serious blight, especially in the great Western landscape parks that are doing daily battle against this form of pollution, which is often perpetuated by visitors themselves.

Minute Man National

Historical Park, Mass. It’s questionable if anyone would hear the “shot heard round the world” today, given the racket generated by the neighboring regional airport, whose busy traffic sounds more like the battles of Lexington and Concord.

Theodore Roosevelt

Island, Washington, D.C. This wooded sanctuary in the middle of the Potomac River is crisscrossed with hiking paths that meander through forests and around marshy ponds. It also lies beneath the flight path of Reagan National Airport. Planes can be deafening.

Yellowstone National Park, Wyo. Many fans of the world’s first national park argue that it is best enjoyed in winter, offering rare solitude and incomparable wildlife viewing. Others stay away, noting the unavoidable presence of snowmobiles -- which belch noxious fumes and whose engines can be heard up to 20 miles away. It’s the only park in the country where rangers are issued ear protection.

Grand Canyon National Park, Ariz. Visitors to this remote plateau have an unparalleled view of one of the wonders of the natural world. They also have noise coming at them from above with aerial tour overflights, and from below with motorized river raft tours. There’s also a passenger train station in the park and year-round tour bus congestion.

Lake Mead National

Recreation Area, Nev. Where the dammed waters of the Colorado River meet three great American deserts. Also where the motorhead crowd -- powerboats, water-skiers and personal watercraft -- share space with kayakers and fishermen. And only 25 miles from Las Vegas.

Hawaii Volcanoes National Park, Hawaii. Hikers here enjoy a multitude of natural sounds -- crashing surf, singing birds and even crackling lava. Unfortunately, they often also hear much more. More than 30,000 air tours, in helicopters and small planes, buzz over Hawaii Volcanoes each year, giving the park one of the highest levels of overflights in the national park system.

-- Julie Cart