The Missoula floods

When the ice sheet dammed a valley in Montana, a lake gathered that periodically broke through the ice dam and emptied westward. J Harlen Bretz proposed the catastrophic floods in 1923 and was dismissed for forty years, because geology was then committed to uniformitarianism — the idea that the past worked only through processes we see today, at today's rates. The field evidence eventually won, and Bretz received the discipline's highest award at ninety-six. The episode has become a standing example in the history of science of a correct answer rejected for breaching a methodological principle rather than the data.