Crew cut, athletic and a war hero, Stewart Udall was a perfect fit with John F. Kennedy's New Frontier. As Secretary of the Interior, he won acclaim for expanding national parks and garnered headlines for leading officials on 50- mile hikes. As a lawyer-lobbyist, Udall stayed in Washington until 1979, when a new cause called him home.
On a stopover in St. George, Utah, the previous year, Udall had heard wrenching tales of death and debilitating illness from cancer afflicting Southwesterners who had lived downwind from the Nevada nuclear-test site from the 1950s to the early '60s. Victims were convinced their...