Geologist J Harlen Bretz spent decades meticulously documenting evidence for his theory that massive Ice Age floods carved the Channeled Scabland of eastern Washington. When he proposed the theory in 1923, he sparked one of the biggest debates in geologic history, and the geologic community ridiculed and scorned his work until critics saw the evidence for themselves. James Gilluly, one of Bretz’s most vocal critics, visited Palouse Falls and said, “How could anyone have been so wrong?” Modern satellite photography would have helped illustrate the theory, because the Channelized Scabland of eastern Washington can easily be seen from space.