My first visit to the Shell Mound, a Unit of the Lower Suwannee National Wildlife Refuge, was sometime in July or August 1996. New to Florida and arriving at the absolute worst time of the year for a visit to any outdoor site in the state, Peg and I began to walk on the Dennis Creek trail, which is adjacent to the mound. Having covered less than a quarter mile in humid ninety-degree heat, we beat a hasty retreat back to the car, pursued by dive-bombing yellow flies and swarms of mosquitos.
We came back more than once. The interpretive signs indicated that the mound was essentially a Native American refuse heap consisting primarily of discarded oyster shells, and it was perhaps as much as 6,000 years old. So huge a refuse heap seemed improbable. Maybe the mound provided a retreat to escape from storm surges; the site is close to sea level and far from any protected uplands. The structure was said to have been altered in modern times, evidenced by a hollow spot on one side where shells were mined for use in road construction. An ancient cemetery on nearby Hog Island was discovered more than a century ago, and in early decades was thoroughly looted by antiquities collectors.
Shell Mound from offshore. The launch ramp can be seen at the water's edge and the mound rises beyond.
No evidence of
burials and no collectable artifacts were ever found on Shell Mound itself and it
had no apparent purpose other than for waste disposal. Despite its rather dull story, the mound is certainly
a testament to the numbers and energy of the people who built it.
The foregoing was the story I carried with me for more than 10 years. Despite any real sense of mystery about Shell Mound, it was still an interesting visit. Close to Cedar Key, it was a place where one could connect easily with the unspoiled waters of the Gulf and nearby shoreline habitats. White pelicans, dolphins, and other charismatic wildlife are often on display, and in the right season, the Dennis Creek trail is an attraction for those interested in natural history. However narrow or broad their interests, most visitors seemed to enjoy at least one trip to Shell Mound.
At the end of the road near the boat launch and fishing pier, one can look back toward the land and see the namesake mound. The road curls around it on the way in, but anyone unaware of what to look for it might miss it. Visitors standing in front of it sometimes ask in puzzlement, “where’s the mound?”
Trail leading up and over the summit of Shell Mound. Its structure of hard packed shells is evident where the vegetation has been worn away.
Decidedly un-mound like from most viewpoints, shell mound shows itself only as a thick clump of oaks and red cedar trees. But despite its modest appearance, at more than twenty feet above the surface here, it is one of the highest points on the entire Gulf of Mexico coast. Climbing on a well-worn packed shell path to the pinnacle provides an unparalleled view out over the marsh. Framed by branches of a live oaks (Quercus virginiana or Q. geminata), a small red cedar (Juniperus virginiana) and a gum bully (Sideroxylon lanuginose) shrub, one looks out over bands of pale green saltgrass (Distichlis spicata) in the foreground near the base of the mound, then farther out a thick gray expanse of black needlerush (Juncus roemerianus), a narrow light band of smooth cordgrass (Spartina alterniflora) at the water’s edge, and then to the blue waters of the Gulf beyond. Across the water lies a chain of narrow islands, one of which contains the ancient cemetery. Visitors inclined to linger during the warm season will be soon discovered by legions of hungry salt marsh mosquitoes (Aedes taeniorhynchus and A. sollicitans). Before fleeing, try to get a deep and almost visceral sense, not of how tall the mound is, but instead of the flatness of everything else, as far as the eye can see.
The view out over the Gulf of Mexico from the summit of Shell Mound. Zonation of marsh vegetation can be seen extending from from the base of the mound as the elevation decreases gradually.
Dramatic as the view from Shell Mound is, and as notable as is its unusual elevation, one cannot truly get a sense of the place without learning more. Its irregular shape makes it difficult to estimate volume, but the structure covers about five acres in all. At about 700 feet in one dimension and nearly 500 feet in the other, its total volume is approximately 150,000 cubic yards, or 4 million cubic feet. That computes to about 30 million gallons, so if its builders had carried up basket loads of oyster shells (it is made mostly oyster shells but also bones and other kinds of shells) holding about a gallon each, it would have taken them 30 million trips. Archaeologists have estimated that more than a billion shells make up the mound. Clearly the place wasn’t built in a day, and a series of major efforts surely went into its construction.
Hog Island viewed from the fishing pier on Shell Mound. This is actually a narrow chain of islands, one of which contains the ancient cemetery on Palmetto Mound. This island chain and Shell Mound were contiguous in times when sea level was lower than it is today.
Aerial photographs show Shell Mound at the end of a long formation that looks like a causeway. Had the ancients built not just the mound, but also constructed a three-quarter mile long causeway to reach it from the mainland? They would have invested a great deal of effort just to reach a waste site.
If enough people lived here to pile up so many shells, one wonders what they did about water. Did they carry fresh water from miles away to meet their daily needs? The Cedar Keys region has been called “the blue desert” because of remoteness from ready sources of fresh water. Each of us contemporary Americans uses between 80 and 100 gallons per day—if we had to carry all of it, we would be daily toting between 600 and 800 pounds. Surely the inhabitants of Shell Mound were able to get by with much less, but carrying the heavy stuff could be a problem, nevertheless. Collecting rainwater in huge pots might have helped but would not have sufficed during much of the year. Or maybe they found freshwater springs that empty into the marsh. Such springs are known at various places in the region, but not close to Shell Mound. Maybe the land area of Shell Mound is sufficient to support dug wells able to provide adequate fresh water. Most islands have fresh groundwater, because less dense fresh water “floats” on top of saline ground water. Trees and other terrestrial plants require fresh water, and their presence on islands indicates that some fresh water is available.
Tantalizing as these questions were, ready answers were elusive.
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