The Wilderness Act of 1964 is the principal legal mechanism for preserving wilderness in the United States. The law now protects over 100 million acres of federal land, half of which is in Alaska. Yet the contested meaning of the term wilderness continues to affect the management of those wilderness areas, and the designation of additional lands as wilderness areas. Much current thinking about wilderness emphasizes the ecological and recreational interests that Congress cited when it enacted the law. These justifications for wilderness preservation are important, but they are incomplete. They are best supplemented by a better understanding of the spiritual values of wilderness. Religious conceptions have long informed American attitudes toward wilderness, beginning with the hostility that early settlers gleaned from Old Testament images of wilderness lands, and later appearing throughout the writings of John Muir. More recently, the witnesses testifying on behalf of the proposed Wilderness Act during the 1950's and 1960's repeatedly sounded spiritual themes, including biblical examples of the values of wilderness. The decades since the enactment of the law have produced a substantial theological literature that explores the meaning of wilderness. This article integrates the writing about the spiritual values of wilderness into the discussions of the management of wilderness areas, relying upon the examples of Alaskan wilderness lands to consider how to identify new wilderness areas and how to manage existing areas.