Ever since the Sierra Club adopted the slogan, "In wildness is the preservation of the world," the text from which it was drawn-Thoreau's 1862 essay "Walking"-has been construed as a tribute to wild places. To some extent this reading keeps faith with sentiments expressed in the essay. At the same time, a closer look suggests that the essay as a whole is really more about the life of the spirit than life in the wild. Despite the popular appropriation of "Walking" as a manifesto of environmentalist advocacy, some critics have questioned the usual view of "Walking." Such observations also have a bearing on Thoreau's legacy as a progenitor of the literary expression of American nature spirituality. The purpose of this essay is to elucidate a particular experiential orientation to this spiritually-inflected notion of wildness, beginning with Thoreau and extending into the work of three literary exemplars of American nature religion-John Muir, Edward Abbey, and Annie Dillard. Ever since the Sierra Club adopted the slogan, "In wildness is the preservation of the world," the text from which it was drawn-Thoreau's 1862 essay "Walking"-has been construed as a tribute to wild places. To some extent this reading keeps faith with sentiments expressed in the essay. At the same time, a closer look suggests that the essay as a whole is really more about the life of the spirit than life in the wild. Despite the popular appropriation of "Walking" as a manifesto of environmentalist advocacy, some critics have questioned the usual view of "Walking." Such observations also have a bearing on Thoreau's legacy as a progenitor of the literary expression of American nature spirituality. The purpose of this essay is to elucidate a particular experiential orientation to this spiritually-inflected notion of wildness, beginning with Thoreau and extending into the work of three literary exemplars of American nature religion-John Muir, Edward Abbey, and Annie Dillard.