All the following are found in the upper course of a river except

Of the options given, ox-bow lakes are not typically found in the upper course of a river. Ox-bow lakes are formed when a meandering river erodes the outer bank of a bend, causing the river to change course and cut off the meander. The abandoned meander then becomes an ox-bow lake. In the upper course of a river, the landscape is characterized by steep gradients, rough terrain, and rapid erosion. V-shaped valleys, interlocking spurs, and waterfalls are common features in this area. Interlocking spurs are ridges of higher land that protrude into the valley and force the river to wind its way around them. Waterfalls are formed when a river falls from a height, creating a plunge pool at the bottom. V-shaped valleys are created by the erosion of the river channel as it cuts its way down through the landscape.