Complex sentence: The watershed of the Pend Oreille in the Newport-Oldtown area is extremely limited, due to a small depression of no more than, which begins one-half mile to the west and south of the river.
Split into simpler sentences: The watershed of the Pend Oreille in the Newport-Oldtown area west of the river is extremely limited. This is due to a small depression of no more than, which begins about one-half mile from the river.