Complex sentence: Great Salt Plains Lake is an artificial lake in Alfalfa County, Oklahoma in the United States named because of the salt flats in the area and for the Salt Fork Arkansas River, which is dammed to form the lake.
Split into simpler sentences: Great Salt Plains Lake is an artificial lake in Alfalfa County, Oklahoma in the United States. It is named because of the salt flats which are in the area and for the Salt Fork Arkansas River which is dammed to form the lake.