The Heart of the Grand Canyon

Bradford Washburn’s (1910–2007) The Heart of the Grand Canyon map was born out of frustration. While visiting that iconic park with his wife Barbara in 1969, Washburn was ‘disturbed’ to find a total lack of detailed maps (Fry, 2019). The best map available then was a topographic sheet at 1:62,500 scale (one inch to the mile) and with 80-foot (24.4 m) contours. Besides lacking detail, this map used the standard symbology found on all US Geological Survey topographic maps, which failed to depict the unique character of the Grand Canyon. Thinking that the three million annual park visitors were being cartographically ill-served, Washburn decided to make a better map. So began an almost eightyear project, one involving family, friends, and volunteers, that culminated with his nowfamous map published by National Geographic. Washburn’s intent was to create a highly accurate map useful to scientific researchers that would also appeal to the layperson. The Heart of the Grand Canyonmap focuses on the main touristic area between Grand Canyon Village on the South Rim and Grand Canyon Lodge on the North Rim (Figure 1). How the map came to be is a remarkable story. Washburn, who was the Director of the BostonMuseum of Science, used his modest research budget at that institution to jump-start the project. Initially, it was a side project that he worked on while taking vacations. Having once worked as an instructor of cartography, Washburn was keenly interested in the latest scientific advancements in surveying and mapping, which meshed with his other passions – mountaineering, exploration, and aerial photography. He had already directed two other projects that resulted in world-class maps: Mount McKinley produced by swisstopo in 1960; and Mount Kennedy produced by National Geographic in 1968. Washburn would again work with these two organizations to complete The Heart of the Grand Canyon map. This is also a story about how working collaboratively can accomplish great things. The mapping had to start from scratch due to concerns about the accuracy of previous surveys done decades earlier. With his improvised team and working in a piecemeal manner depending on their schedules, Washburn set out to establish a control network to serve as a framework for ‘resurveying’ the canyon. He based the new control network on five first-order triangulation stations on the North and South rims that were known to be very accurate. The network was then extended, using theodolites and laser rangefinders, to the tops of prominent pinnacles and buttes visible from lower places within the canyon. Helicopters provided access to the more vertiginous crags. The resurveying also involved leveling (to determine elevation) and walking trails with distance measuring wheels. Field work took place from 1971 to 1975, including 144 days spent in the field and 712 helicopter landings (Washburn, 1978).