“Riding Like the Wind: The Life of Sanora Babb” by Iris Jamahl Dunkle Photo: University of California Press Like many Americans, biographer Iris Jamahl Dunkle’s introduction to the Dust Bowl was shaped by reading John Steinbeck’s “The Grapes of Wrath.” Her grandmother, who lived through the storms, dismissed it for depicting migrants as “helpless victims.” So when Dunkle discovered another Dust Bowl novel, Sanora Babb’s “Whose Names Are Unknown,” she was moved to find a humanized portrayal...