Two thirds of the large area in what local residents call "mainland Monroe" is uninhabited by virtue of being part of the Everglades National Park, and the remainder by the Big Cypress National Preserve in the northeastern interior. The area, officially named Cape Sable Census County Division, is virtually uninhabited. As of the census of 2000, this area had 86.9 percent of the county's land area (866.25 out of ), but only 0.075 percent of its population (60 out of 79,589). The Census Bureau defines this area as Census Tract 9701 of Monroe County, Florida. With a population density of only 0.0693/sq mi (0.0267/km2), if it were a separate county or county-equivalent, only the Yukon-Koyukuk Census Area of central Alaska would have a lower population density out of all U.S. counties.