America's rivers are its lifeblood, but as infrastructure across the nation fails and climate change pushes rivers and seas to new heights, we've arrived at a critical moment in our battle to tame these forces of nature. Having spent two years traveling the heartland, Tyler Kelley shares what he learned from the people whose lives and livelihoods depend on these waterways, including the master of the decrepit dam on the Ohio River, a Missouri woman whose community was flooded by Army engineers, and the man responsible for keeping North America's greatest river under control.