From the enactment of the National Park Service Organic Act (the Organic Act or the Act) in 1916 until a 1998 decision by a federal district court in Utah, the National Park Service (NPS) had managed national parks without resolving theseeming contradiction between the Act's directive to conserve park resources "unimpaired" and its simultaneous directive to provide for visitors' "enjoyment" of those resources. Uncertainty, confusion, and disputes about the inevitably conflicting implications of these mandates were virtually guaranteed by the text of the Act, which requires the NPS to—

promote and regulate the use of [national parks] by such means and measures as conform to the fundamental purpose of the said parks, . . . which purpose is to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations.