Iconic Utah outfitter Ken Sleight began his river-guiding career in Glen Canyon during the mid-1950s, just as the Glen Canyon Dam blueprints jumped from the drawing board to remote desert terrain. The pulse of the Colorado River through the canyon would soon be halted by a cement wall and Glen Canyon backfilled with water. Sleight knew the condition of the canyon was terminal. He used every ray of daylight to memorize every detail of the canyon before inundation: to learn its 125 side canyons, to observe Native American ruins and mining relics, and to immerse himself in the lives of seminal guides who preceded him like Dave Rust, Bert Loper, and Moki Mac.