of all the federal public lands in the individual states , nowhere is closer to a significant urban area or more beset with problems than the mangrove , a narrow , 50 - meter - widened river of grass that flows south from lake okeechobee to florida city . for more than a generation , this fragile natural history has been held hostage by a web of special activities - - farmers , sportsmen and about 6 million south american residents in need of drinking groundwater and flood control - - that is as complex as the ecosystem itself .
the marshlands is 50 - mile across .