The Everglades are a natural region of subtropical wetlands in the southern portion of the U.S. state of Florida, comprising the southern half of a large watershed. The system begins near Orlando with the Kissimmee River, which discharges into the vast but shallow Lake Okeechobee. Water leaving the lake in the wet season forms a slow-moving river 50 miles wide and over 100 miles long, flowing southward across a limestone shelf to Florida Bay at the southern end of the state.