Barry Goldwater looks positively blissful. It’s the summer of 1940, and 31-year-old Barry is deep into a journey along the Colorado River that will make him just the 73rd person to travel through the Grand Canyon by boat. 

Barry is virtually unrecognizable in the photograph. Wearing a T-shirt, he gazes into the distance, his eyes alive and his smile serene. The high forehead appears familiar, but Barry’s trademark jutting jaw is concealed by a thick, dark beard, the kind men grow when the closest mirrors are miles away and wives won’t be seen for several weeks more.

Barry had left behind his wife, Peggy, in San Diego that July with the couple’s three small children, including son Michael, born just four months earlier. Peggy didn’t want her husband to go on the trip, and Barry confessed a measure of guilt at temporarily abandoning his young family. But he also couldn’t resist the opportunity to challenge the fabled rapids with pioneering river runner Norman Nevills, to satisfy what he described as a “long smoldering desire to make the trip down the Colorado River...