In the latter half of the nineteenth century, especially between 1859 and 1872, Union officers and enlisted men, scientists and explorers, artists and writers traveled westward. Surveyors appraised and mapped; expeditionary members explored and then wrote, hoping to convey the wonders they had witnessed. The western wilderness was an enormous expanse, one that as easily represented commercial possibilities as it did a new ideal. Nevertheless, the western wilderness also mesmerized and inspired, provoking a type of awe and wonderment in its languorous canyons, exploding fumaroles, bubbling hot springs, and soaring granite spires. From the Rockies to the Sawtooths, from the Cascades to the Tetons, the mountains of the American West mystified and hypnotized those who saw them. The Sierra Nevadas, in particular, became the locus for artists and writers. Their paintings and publications, in turn, inspired entire groups to travel to the Yosemite Valley in order to ponder the sublime beauties of Nature found there. Through the paintings and sketches of Albert Bierstadt and Thomas Moran, and through the meticulous journal entries and travel narratives of Clarence King and John Muir—whose work as a Naturalist eventually helped establish the Valley as a National Park—Yosemite captured the imagination of the American people, as its spires, cliffs, and waterfalls had been artistically transformed from mere tourist destinations into sites of divine revelation.