Complex sentence: According to the 2010 Census, the county had a total area of, of which (or 96.88%) is land and (or 3.12%) is water, making it the fourth-largest of the state's 21 counties in terms of area.
Split into simpler sentences: According to the 2010 Census, the county had a total area of, of which (or 96.88%) is land and (or 3.12%) is water. It is the fourth-largest of the state's 21 counties in terms of area.