Geologists classify valleys in two ways: first according to the
overall pattern made by the stream valleys in a region, and second
according to age based on the shape of the valley profile.
The tributaries that feed the Bryant form in general a dendritic
or treelike pattern, repeatedly branching upstream into smaller
tributaries, much like the branches on a tree. However, in detail
these apparently random branchings have a parallelism that reflects
the joint and fault pattern of the rocks through which they flow.
The structure of the bedrock exerts a subtle influence on the pattern
of the watershed.