Complex sentence: The West Branch Oswegatchie is more slower-moving than the Middle Branch, but the still waters such as Long Pond, Mud Pond and Long Level are separated by hard-to-traverse rapids and/or waterfalls.
Split into simpler sentences: The West Branch Oswegatchie is slower-moving than the Middle Branch. But the still waters such as Long Pond, Mud Pond and Long Level, are separated by hard-to-traverse rapids and/or waterfalls.