Collier County is a count located in the state of Florida. As of 2000, the population was 251,377. Collier County was created in 1923 from Lee County. It was named for Barron Collier, a New York City advertising mogul and real estate developer.According to the U.S. Census Bureau, the county has a total area of 2,305 square miles (5,970 km²), of which, 2,025 square miles (5,246 km²) of it is land and 280 square miles (724 km²) of it (12.13%) is water. Virtually the entire southeastern portion of the county lies within the Big Cypress National Preserve. The northernmost portion of Everglades National Park extends into the southern coastal part of the county.