Lake Okeechobee, locally referred to as The Lake or The Big O, is a freshwater lake in Florida. It is the seventh largest freshwater lake in United States and the second largest freshwater lake contained entirely within the lower 48 states. Okeechobee covers 730 square miles (1,890 km˛), approximately half the size of the state of Rhode Island, and is relatively shallow, with an average depth of only 9 feet (3 m).