Complex sentence: Fed by glaciers at the headwaters, the Ivishak flows northeast, then northwest, through the Philip Smith Mountains and the northern foothills of the Arctic National Wildlife Refuge, and joins the Sagavanirktok River on the coastal plain south of Prudhoe Bay.
Split into simpler sentences: Fed by glaciers at the headwaters, the Ivishak flows northeast, then northwest, through the Philip Smith Mountains and the northern foothills of the Arctic National Wildlife Refuge. It enters the Sagavanirktok River on the coastal plain south of Prudhoe Bay.