The Grand Canyon runs through land that is home to several Native American tribes, including the Havasupai, who actually live in and near the boundary of the canyon.

According to the Havasupai, the Canyon was supposed to remain hidden and remote. Increasing exposure of the canyon to outsiders conflicted with a Havasupai prophecy that stated the land and water would become polluted if the public gained access to the area.

In 1932, The US Congress named the Grand Canyon National Monument as a National Park.

After many years of legal struggle, the Havasupai prevailed, and their seat of government and reservation lies at the end of an 8 mile descent into the Grand Canyon in Supai, where they assist the Nation Parks and the US Department of Interior in preserving the Canyon.

The Havasupai now help the National Park Service run the park, and the NPS has taken pains to preserve the culturally and spiritually sensitive heritage of the park.

More Info: en.wikipedia.org