Grand Canyon National Park is administered in accordance with the National Park Service's organic legislation, Grand Canyon National Park's enabling legislation, the National Park Service concessions laws, and a number of other public laws, Executive Orders, and agency regulations and policy guidance.

The Grand Canyon was proclaimed a National Monument by President Theodore Roosevelt in 1908. In creating what would later become Grand Canyon National Park, President Roosevelt recognized the Grand Canyon as "an object of unusual scientific interest, being the greatest eroded canyon in the United States, and it appears that the public interest would be promoted by reserving it as a National Monument."

In 1916, Congress created the National Park Service to manage a growing list of national parks, monuments, and historic sites. The National Park Service Organic Act of 1916 charges the National Park Service with a dual mandate of protecting and regulating the use of the national parks "by such means and measures as conform to the fundamental purpose to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment for the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations."

Congress reaffirmed this standard of protection in the Redwoods Act of 1978, when it declared and directed that the "promotion and regulation of the various areas of the National Park System . . . shall be consistent with and founded in the purpose established by the [Organic Act] to the common benefit of all the people of the United States." Congress further declared that the administration of the national parks is to be conducted "in light of the high public value and integrity of the National Park System" and "shall not be exercised in derogation of the values and purposes for which these various areas have been established, except as may have been or shall be directly and specifically provided by Congress."

The Grand Canyon became part of the National Park System in 1919, when Congress expanded and upgraded the Grand Canyon National Monument established in 1908 by President Theodore Roosevelt, thereby creating Grand Canyon National Park. The Act of February 26, 1919 "reserved and withdr[ew] from settlement, occupancy, or disposal under the laws of the United States and set apart as a public park for the benefit and enjoyment of the people" land in the State of Arizona under the name of Grand Canyon National Park. The Act further directed that the National Park Service assume the responsibility for the administration, protection, and promotion of the Park, and authorized the National Park Service to grant commercial concessions "for the accommodation or entertainment of visitors."

Within the confines of the Organic Act's dual mandate, the National Park Service has been given broad authority by Congress to manage parks and to determine what resource use opportunities and levels of use are appropriate. The Organic Act directed the Secretary of the Interior to "make and publish such rules and regulations as he may deem necessary or proper for the use and management of the parks, monuments, and reservations under the jurisdiction of the National Park Service." Pursuant to this authority, the National Park Service has promulgated regulations governing whitewater river trips through the Grand Canyon.

The National Park Service's administration of the park system also is guided by the agency's internal management policies. These policies provide direction for decision-making and cover a wide range of subjects, including park system planning, natural and cultural resource management, commercial visitor services, park uses, and wilderness preservation and management. Among other things, they recognize that providing opportunities for appropriate public enjoyment is an essential part of the Service's mission, and provide that, in exercising its discretionary authority, the Service will allow uses that are "appropriate to the purpose for which the park was established" and that "can be sustained without causing unacceptable impacts to park resources or values."

In addition to legislative mandates, regulations, and management policies, the National Park Service manages the park system pursuant to park-specific management plans. The National Park Service has developed the Colorado River Management Plan to guide the management of the Colorado River corridor through Grand Canyon National Park. This is the official management document that controls and defines the public's access to and acceptable activities along the Colorado River within the Grand Canyon. Other undeveloped areas of the Park are managed under a separate Backcountry Management Plan and other plans. The National Park Service is currently engaged in an effort to update the Colorado River Management Plan.