Canyon de Chelly is unique among National Park service units, as it consists entirely of Navajo Tribal Trust Land which remains in the ownership of the Navajo Nation and is home to the canyon community, while park matters are administered by the National Park Service. Access to the canyon floor is restricted, and visitors are allowed to travel in the canyons only when accompanied by a park ranger or an authorized Navajo guide.  The only exception to this rule is the White House Ruin Trail. The 20 minute walk down the trail gives one a real sense of moving back in time.