One of the features found in the upper course of a river is

The feature found in the upper course of a river is a gorge. This is a narrow and steep-sided valley that is usually formed as a result of erosion by fast-flowing water over a long period of time. The river in the upper course has a high gradient, and the water flows with greater force and velocity, thus eroding the rock and soil more efficiently. The rocks in the upper course of a river are typically harder, and the river may have to cut through them, forming a narrow and steep-sided valley known as a gorge. Gorges are often characterized by vertical cliffs or near-vertical cliffs, and they may have rapids and waterfalls where the river's gradient is steeper.