As the Le Sueur River cuts down deeper through till and bedrock, the adjacent hillslopes are obliged to follow. Bluffs erode by slumping and landsliding, and ravines form, cutting back into the high-standing agricultural uplands. If we first constrain the rate of knickpoint (local, sharp changes in channel slope) migration, we can use the Le Sueur River as a grand, natural experiment to understand bluff retreat and ravine development.