In which part of the river system would you typically find interlocking spurs?

Interlocking spurs are typically found in the upper course of a river. This part of the river system is characterized by steep gradients and rugged terrain, which leads to the formation of sharp bends and valleys. As a river carves its way through the landscape, it often cuts around areas of higher elevation, creating protrusions or "spurs" that alternate from either side of the river. This results in the interlocking appearance as the river flows between them.

In contrast, the middle and lower courses of a river have different characteristics. The middle course usually features meandering patterns due to a gentler gradient, leading to wider, more fluid river shapes. The lower course, close to where the river meets a body of water, typically exhibits a flat landscape and features like deltas, where sediment is deposited rather than the rugged terrain seen in the upper course. The delta region consists of sediment deposition at the river's mouth and does not exhibit the interlocking spurs phenomenon, which is specific to the upper course.