Simplify the following text for a Grade 5 native English-speaking person.
Original: Juneau County has an area of 804 square miles , 37 of which is water , according to the United States Census Bureau .
Simplified: According to the U.S. Census Bureau , the county has a total area of 804 s , of which 768 s is land and 37 s ( 4.54 % ) is water .