What Are U Shaped Valleys? A U-shaped valley is an geological formation that has steep, high sides and a rounded or flat valley bottom. These valleys are formed by glaciation. They are often filled with lakes rivers, sandtraps, sandtraps on golf course kettle lakes (water hazards), or other natural features. https://www-sofasandcouches-com70782.blogoscience.com/35969963/what-is-sectional-u-shape-and-why-is-everyone-speakin-about-it