Six Mile Cypress Slough Preserve is an over 3,500-acre wetland ecosystem measuring 11 miles long and averaging 1/3 mile wide. It supports a diversity of plants and animals, including a number of endangered species, and serves as an important migrant stopover and wintering habitat for many birds. As a linear wetland, it also provides a wildlife corridor through the surrounding country. The slough functions as a natural drainage way, collecting rainwater runoff from many square miles of watershed. During the wet season, June-November, water 2-3 feet deep makes the slough comparable to a wide but shallow stream. As water flows slowly southwest through the slough, sediment settles out and pollutants are absorbed by plant life, cleaning the water before it reaches the Estero Bay Aquatic Preserve.