You would expect the hanging wall of a normal fault to form the floor of a valley.

Here's why:

* Normal Faults: These faults are caused by tensional forces pulling the crust apart. The hanging wall (the block above the fault plane) moves downward relative to the footwall (the block below the fault plane).

* Valley Formation: As the hanging wall drops, it creates a depression or a valley.

So, in essence, the hanging wall is the side that "hangs down" and forms the valley floor.