Hal Shelton Revisted: Designing and Producing Natural-Color Maps with Satellite Land Cover Data

Tom Patterson, US National Park Service
Nathaniel Vaughn Kelso, National Geographic

Published in Cartographic Perspectives (No. 47, Winter 2004), the journal of the North American Cartographic Information Society (NACIS).



It is the authors’ hope that this paper spurs renewed interest in natural-color mapping. The digital procedures presented in this paper, we believe, will permit many more cartographers to make natural-color maps. The combination of Adobe Photoshop software and raster land cover data now provides a means of producing attractive natural-color maps that, dare we say, rival those made by Shelton. But good looks are only part of the story. Compared to manual methods, digital production yields maps of much greater accuracy. Map readers can confidently assume that the pixels representing forests, fields, and fells are where they should be. New land cover data, such as MODIS VCF, which blends land cover categories into one another, provides readers with insights about the indistinct vegetative boundaries found in nature. For example, the colors representing forest and herbaceous land combine in Africa to form a third category: savannah. The amount of blending between, say, green forest and tawny grassland allows readers to gauge intuitively the relative vegetative content for any given area. And the use of shaded relief provides additional insights about the relationship of topography and vegetation. Making complex geospatial information such as this easy for inexperienced map-readers to grasp is what cartographic communication is all about. That natural-color maps are also visually pleasing and attract and hold our attention only adds to their effectiveness, in the words of Shelton, as “instruments of communication.”

Digital production has largely removed the economic and time disincentives that have been associated with the making of natural-color maps in the past. Most of the data discussed in this paper is in the public domain and available online for free (see Appendix B). Adobe Photoshop, although relatively expensive, is already part of the software toolkit on many cartographers’ computers. Most of the time needed for making natural-color maps digitally is spent in tedious data management chores: finding and downloading large data files, converting obscure formats, and reprojecting and registering shaded relief and land cover data. Compared to the manual era, however, the time needed for making a digital natural-color map now requires days rather than weeks or months. Once the data is ready, the procedures and examples we have described explain how to design and produce natural-color maps. Switching your thought processes from data management mode to a more creative mindset is a key to success. Because critical design decisions occur at the end of the project when time is often running short, one must resist the temptation to rush to completion.

While one no longer must be an accomplished artist/cartographer to make natural-color maps, good design sense and grounding in physical geography are still necessary prerequisites. Because of our tendency to overuse new design trends, cartographers must be mindful that natural-color maps are not applicable to all physical mapping situations. Shelton’s claims of arbitrariness aside, hypsometric tints are acceptable, and they excel at showing elevation zones and topographic forms, if that is what one wants to emphasize on a map. Cartographic choice is a good thing.

Hal Shelton revisited: returning to art

Because this article began with a discussion of Hal Shelton’s early years in cartography, it is fitting that it should end with a few words about his later career. Art has become increasingly important in his life. After easing out of his relationship with the Jeppesen Map Company, Shelton turned his attention to painting ski area panoramas. His work included many of the major resorts in North America and a panorama of Grenoble, France, used by ABC TV for the 1968 Olympics. For his most famous panorama, “Colorado: Ski Country USA,” Shelton received a lifetime ski pass to all resorts in Colorado, which he has put to good use for decades.

Shelton now devotes his time to painting—a return to his early art interest before it was interrupted by some 40 years of cartography. When creating art, Shelton finds that he is

“responding to a broader spectrum of realities than I was able to do in cartography.”

The artistic and cartographic careers of Shelton came full circle in 1985 with an unusual request from the U.S. Library of Congress. The Geography and Map Division commissioned him to paint a landscape using the techniques he learned as a natural-color cartographer. Having applied his art training to cartography for so many years, the idea was for cartography to give something back to art. The result was “Canyon Lands,” a 1.9-meter-wide triptych displayed behind the reference desk in the Map Reading Room (Figure 22). Although at the time of this writing “Canyon Lands” no longer is on display, you may view it privately by asking one of the librarians. The effort is worthwhile. Hal Shelton’s “Canyon Lands” repays cartography’s debt to art most generously.

Figure 22. “Canyon Lands” by Hal Shelton. Millard Canyon, Utah, dominates the center of the scene and the snowcapped LaSal Mountains are faintly visible on the right horizon. The vertical triptych joints do not appear because of digital compositing. Courtesy of Library of Congress.


Just as the making of natural-color maps is a team effort, so too is the writing of an article about them. The authors wish to thank the following people for their kind assistance: John Hutchinson, USGS EROS Data Center; Marc Weinshenker, Angie Faulkner, Mark Muse, Melinda Schmitt, and Ed Zahniser, US National Park Service; Christine Bosacki, Nystrom; Bernhard Jenny, ETH Zürich; Linda Schubert, Rand McNally & Company; Jim Flatness and Ronald Grim, US Library of Congress; Tibor Tóth; and, most importantly, Hal Shelton and his wife Mary.

References Appendix A
Shelton Collection,
Library of Congress
Appendix B
Internet resources


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