America's National Park Service is responsible for protecting the Grand Canyon from the effects of so many visitors.

VOA: special.2009.10.07

But when the Grand Canyon National Park was created the law confined them to the canyon floor, a tract of 188, 000 acres out of their original 2m.

ECONOMIST: Indian tribes

When several hundred rather destructive donkeys were to be shot in the Grand Canyon national park, the fund paid for them to be lifted out by helicopter.

ECONOMIST: Cleveland Amory | The

Arizona River Runners has operated since 1970 as an authorized concessioner of Grand Canyon National Park, and its seasoned staff takes hundreds of travelers through the canyon each year, offering a variety of experiences, from 3-day samplers to 15-day descents of the entire 225-mile Canyon.

FORBES: Grand Canyon Rafting