Krakauer's recounting of certain aspects of the climb has generated criticism, both from some of the climb's participants and from renowned mountaineers such as Galen Rowell. Much of the disputed material centers on Krakauer's accounting of the actions of Russian climber and guide Anatoli Boukreev. An experienced high-altitude climber and guide for Scott Fischer, Boukreev descended the summit prior to his clients, ostensibly out of concern for their safety and in preparation for potential rescue efforts. Boukreev later mounted repeated solo rescue efforts, saving several lives. In his book, Krakauer acknowledged Boukreev's heroism in saving two climbers' lives, but questions his judgment, his decision to descend before clients, not using supplementary oxygen, his choices of gear on the mountain, and his interaction with clients. Boukreev provides a rebuttal to these allegations in his 1997 book "The Climb".