Back when men still believed the “weaker sex” were inferior climbers, Arlene Blum led a women’s ascent of Annapurna, the world’s tenth-highest peak. The 1978 climb put the first women—and first Americans, period—on the summit, but the death of two climbers sparked a controversy. Outside contributing editor Florence Williams talks with Blum and Alpinist editor in chief Katie Ives about why the expedition continues to inspire climbers and stir debate.