Two of my rock-collecting friends recently dropped off several hundred pounds of old United States Geological Survey topographical maps that had been thrown out by universities. Most of my basement is occupied with tables covered with stacks of these large maps. Something about their appearance, their purpose, and their very survival for over a hundred years brings to them a significance that defies obsolescence. The paper itself has aged to a sepia tone and yet maintains a glossiness not seen on more modern editions. The elevation contours vary in depth of color, but are usually a burnt reddish-brown. Forested lands aren’t green on the earliest maps, but when green arrives, it’s a mellower shade than the current graphic hue. Water is a deeper shade of blue. The Mississippi River delta makes for some of the loveliest images of braided watercourses rendered by man. All these colors have a luster that seems to elevate lake and woodland areas off the paper.

Some of the more featureless areas are attractive for the old typeface used for place names. A sparsely populated place in the Southwest is labeled “Memroy’s Ranch” since it was the only settlement for many miles. The flatness of the Midwest facilitated the rectilinear road layouts, with houses (tiny black squares) so widely scattered they had to be farms. The rare instances of Midwest roads not oriented north–south and east–west appear where a city grew up on a river that didn’t feel like running due north or south. Even then, the roads ran parallel and perpendicular to each other, but the grid was rotated, snugged up against its lifeline.

“Big city” maps (of Los Angeles, San Jose, and New Orleans) from the 1890s document the growth of streets and even buildings. Some quadrangles went through five or six editions between the late 1880s and 1945. Mountains, scarps, and gullies instantly communicate the enormous forces that shaped them over eons. Different versions of the same area seem identical until I discover that a delta sandbar shifted a bit, or a river altered course. In the case of Lake Yellowstone, the “Western Thumb,” a large bay at the lake’s southwestern edge, shrank slightly by the 1930s and is now labeled the Western Leg. Such changes are only detectable by laying one map on the other and trans-illuminating the two with a bright light. Whether they depict the convoluted topography of eroded badlands or the structured imprint of humanity, these maps tell the story of an evolving American landscape.