In 1971, Walt soloed Turnback Canyon on the Alsek (at the time was considered by some as whitewater’s Everest), among the biggest accomplishments of its time. His solo descent was ahead of its time and became significant in terms of its solo, self-supported extreme of exploration. His article chronicling his solo descent, featured in Sports Illustrated, propelled him to almost a cult hero overnight making him the legend that became the face for the public epitomizing big water river running. He holds numerous early and big water descents including the Middle Fork of the Flathead (Montana), and the South Fork of the Salmon and the Bruneau (Idaho).
ABC’s American Sportsman produced short films of the paddling doctor (he was a surgeon) running the Colorado (1975) and the Susitna (1977). He was also featured in The Edge, a feature length film about adventure sports (1976). Walt died on the South Fork of the Payette in Idaho in 1978, pinned on a submerged log.