Yes, the Everglades is primarily a freshwater marsh. It is the largest subtropical freshwater marsh system in the United States, spanning 1.5 million protected acres in southern Florida. But calling it simply “a marsh” undersells what’s actually there. The Everglades contains nine distinct habitats, and while sawgrass marsh dominates the landscape, it also includes swamps, prairies, forests, and coastal marine environments.
What Makes It a Marsh, Not a Swamp
The distinction between a marsh and a swamp comes down to vegetation. Marshes are dominated by grasses and other herbaceous (non-woody) plants growing in waterlogged soil. Swamps are dominated by trees, like cypress or red maple, that tolerate standing water. The Everglades fits the marsh definition because its defining plant is sawgrass, a tall sedge that historically covered 60 to 70 percent of the entire landscape. The rest was a mix of wet prairies, open-water sloughs with submerged vegetation, and scattered tree islands.
That said, the Everglades does contain swamps within its boundaries. Cypress swamps and mangrove swamps are both part of the system. The mangrove ecosystem along the coast is the largest continuous mangrove system in the Western Hemisphere. So while the Everglades as a whole is classified as a freshwater marsh, it’s more accurate to think of it as a mosaic of wetland types with marsh at its core.
The “River of Grass” and How Water Moves
Writer Marjory Stoneman Douglas famously called the Everglades a “river of grass” in her 1947 book, and the name stuck because it captures something essential about how the system works. Unlike most wetlands, which are fed by rivers and streams, the Everglades relies on sheet flow: a broad, shallow layer of water creeping slowly across the landscape from Lake Okeechobee toward Florida Bay.
That flow is remarkably slow. U.S. Geological Survey measurements found that the average velocity is about 1.15 centimeters per second, with 90 percent of daily flow speeds falling between roughly 0.5 and 2.3 centimeters per second. For perspective, that’s slower than most people can perceive visually. The water moves this slowly because the land is almost perfectly flat (the slope is about one foot per mile), and dense submerged and emergent vegetation creates enormous resistance. The result is a vast, shallow wetland where water is always present but rarely rushing.
Nine Habitats in One Ecosystem
The National Park Service identifies nine distinct habitats within Everglades National Park. Here are the major ones:
- Sawgrass marshes: The signature habitat, with dense stands of sawgrass growing in shallow water over peat or marl soils.
- Freshwater sloughs: Deeper, slow-moving channels of open water that act as the main pathways for sheet flow.
- Freshwater marl prairies: Shorter-grass wetlands in the southern Everglades where the soil is a light-colored calcium-rich sediment called marl.
- Cypress swamps: Stands of cypress trees growing in standing water, often forming dome-shaped clusters.
- Hardwood hammocks: Small, elevated islands of broad-leaf trees that sit just high enough to stay dry in all but the wettest years.
- Pinelands: Fire-dependent pine rockland communities growing on exposed limestone. These are one of the most endangered plant communities in the world.
- Mangrove forests: Salt-tolerant trees lining the coast, forming a buffer between freshwater marsh and open ocean.
- Coastal lowlands and marine/estuarine zones: Where freshwater meets saltwater along Florida Bay and the Gulf of Mexico.
These habitats blend into one another rather than having hard borders. Water depth, soil type, and salinity shift gradually across the landscape, and the vegetation follows.
What’s Underneath the Marsh
Two types of soil define the Everglades marsh, and which one you find depends on how long water sits on the surface in a given area. In the wetter northern regions, where the ground is submerged more than 330 days per year, the soil is peat, formed by the slow, oxygen-starved decomposition of plant matter. In the drier southern marshes, where the ground is wet for as few as 120 days per year, the soil is marl, a light-colored mix of silt and fine-grained calcium carbonate. Both soil types sit on top of highly porous limestone bedrock, which acts as the region’s main aquifer.
Wildlife Shaped by the Marsh
The marsh character of the Everglades directly shapes which animals thrive there. The system’s most iconic species depend on open, grassy wetlands rather than forested swamps. The Everglade snail kite, a federally endangered raptor, feeds almost exclusively on apple snails found in freshwater marshes. Wood storks rely on shallow, receding water levels to concentrate fish into pools where they can feed. American alligators create “gator holes” in the marsh that become critical dry-season refuges for fish, turtles, and wading birds.
Other notable species include the American crocodile, which inhabits the brackish coastal areas where marsh meets mangrove, and the Florida panther, which is rare even within the park but depends on the broader Everglades ecosystem for habitat. The West Indian manatee is common in the park’s estuarine waters. All six of these species are listed as either threatened or endangered under federal law, and their survival is tied to the health of the marsh and its water flow.
Why People Confuse It With a Swamp
The Everglades gets called a swamp constantly, in casual conversation and even in older government documents. Part of the confusion is historical. Early settlers saw a vast, buggy, waterlogged landscape full of alligators and assumed “swamp.” Developers in the early 1900s actively promoted the idea that the Everglades was a useless swamp that should be drained for agriculture, and that framing stuck in popular culture.
The presence of actual swamps within the Everglades adds to the confusion. If you visit areas with towering cypress trees draped in Spanish moss, it looks and feels like a swamp because, locally, it is one. But those cypress swamps are relatively small pockets within a much larger grass-dominated system. The Everglades, taken as a whole, is a marsh, and the distinction matters because marshes and swamps respond differently to changes in water levels, fire, and nutrient pollution. Restoration efforts depend on understanding that the system was built by shallow, slow-moving water flowing through grass, not through forest.