What Are U Shaped Valleys? A U-shaped valley is a geological formation that has steep, high sides as well as flat or rounded valley bottom. These valleys are formed by glaciation. They are often filled with lakes, rivers, sandtraps on golf course, kettle lakes (water hazards) or other natural features. https://couch90055.laowaiblog.com/29179499/10-tips-for-sectional-u-shape-that-are-unexpected