Where is a stream most likely to form a narrow valley?

A stream is most likely to form a narrow valley in areas with steep topography, such as mountainous or hilly regions. As the stream flows downhill, it erodes the surrounding rock and soil more rapidly, creating a V-shaped valley. This process is enhanced by factors like the geology of the area, which may include harder rock that resists erosion. Over time, the continuous flow of water carves out a narrow and steep-sided valley.