After the Civil War, four geological and geographical surveys, later called the Great Surveys, Undertook the massive task of finding out what lay west of the hundredth meridian in the vast American wilderness. Parties led by Ferdinand Vandiveer Hayden, medical doctor turned geologist, Clarence King, aristocrat and intellectual, John Wesley Powell, conqueror of the Colorado River, and Lieutenant George M. Wheeler, determined military man and scientist, roamed over the wild country during the years 1867-79, observing, analyzing, mapping, and at the end of each season, returning to Washington to publish their results.

For the first time in book form, Richard A. Bartlett has recreated for the reader the hardships, both physical and financial, the discoveries, and the high adventures of the bold, headstrong, and often brilliant men of the Great Surveys as they climbed the Rockies, explored the Yellowstone, or battled the Colorado.