Machaba Balu Preserve is a ten-thousand-acre protected marsh and island complex in northeastern Florida near Jacksonville, where the Nassau, Saint Marys, and Saint Johns Rivers approach the Atlantic. Created in 2002 by the Nature Conservancy through land purchases mostly from Alcoma Corporation, it includes seventy-seven islands and extensive marsh tracts. Its modern Timucua name means “saved marsh,” reflecting a landscape of estuaries, tidal creeks, and wetlands shaped by fresh and salt water. The preserve is important for biodiversity, fish spawning and hatchery habitat, and wildlife ranging from manatees and sea turtles to Florida black bears and red-cockaded woodpeckers, while remaining vulnerable to pollution from nearby coastal development.