Prior to the 1850s, no large-scale maps of the Grand Canyon existed. Maps covering the region were predominantly small-scale products, crudely generalizing vast swathes of territory. Most maps relegated the location of the Grand Canyon itself to a conspicuous “blank space”. In the mid-19th century era of US territorial expansion, fueled by the ideological imperatives of Manifest Destiny, such glaring omissions of cartographic detail demanded a corrective filling-in. A map drawn by the pioneering cartographer Frederick Wilhelm von Egloffstein as part of the 1857-1858 Ives survey marked the first successful effort to map the Colorado River, and, by extension, its Grand Canyon, in any meaningful detail. A decade later, in the summer of 1869, a one-armed Civil War veteran named John Wesley Powell famously led a group of nine men to explore and conduct a more thorough topographic survey of the still mysterious lands abutting the river. In the decades following the Ives and Powell surveys, the motivations for mapping the Grand Canyon have changed, as have the technologies, the techniques, and the very maps themselves. From maps of increasing topographic accuracy, to fancifully illustrated pictorial maps, to National Park Service maps, to geologic maps, to interactive 3D web maps, and everything in between, the geography of the Grand Canyon region has been the subject of a multitude of diverse manifestations of cartographic representation.