Traces of the Ancients in the Lower Suwannee Region: Part II. Shell Mound: The Structure

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.

 

Traces of the Ancients in the Lower Suwannee Region Part I. Cat Island

The desire to learn more about the ancient people who inhabited Florida came not from direct observations in the field. Instead, my curiosity was fed by the fascinating tales woven by University of Florida archaeologist Ken Sassaman. In a series of presentations to the Cedar Key community describing his investigations, he peeled back more and more of the mysteries surrounding the pre-Columbian mound builders of the southeastern coast, focusing on close to home features.

 The ongoing discovery of the pre-history of Shell Mound and the significance of the mound as an ecological feature is a late chapter in the continuing education of a naturalist. Shell Mound, on the Gulf of Mexico about four miles north of Cedar Key, is an ancient Native American structure that pre-dates the European settlement of the western hemisphere. In addition to its undoubted interest to students of archaeology, the mound has unique features that qualify it as a subject worthy of the attention of natural historians.

 

Cat Island, Florida, December 6, 2011

 The paddle over to Cat Island from the Town of Suwannee wasn’t too bad. We had a following wind and moderate, perhaps two-foot, waves. I wasn’t an experienced kayaker and was uneasy with waves. We were paddling in the Gulf of Mexico where very large waves are possible. Although the waves weren’t particularly frightening, I knew a bit more wind could whip up bigger ones and take me well out of my narrow comfort zone. 

 I had recently begun kayaking to help a partner develop a series of paddling guides to highlight kayaking opportunities in the Lower Suwannee and Cedar Keys National Wildlife Refuges. We hoped paddlers would better appreciate the natural history of the refuges and see their paddling trails as more than watery exercise routes.

 

Approaching Cat Island from the south.

Our only near-disaster happened just as we reached Cat Island. I was the first ashore, and my kayak glided in to the beach, stopping abruptly with a thud on the hard-packed sand. I’ll wait until the others arrive, I thought, but my landing was instantly followed by the feeling of water gushing over the back of the boat and flooding the cockpit. The boat stopped, but the following waves did not, the boat was overtopped, and I was sitting in water, mostly soaked from the waist down. The others had a good laugh when I told them what happened.

 Now that we had arrived, I wondered what kind of place this was. The narrow beach on which we landed abuts an eroded bank a bit taller than me. A short but steep scramble took me to where I could look around. I struggled to take in the panorama before me. I looked right and left, then right and left again. The island was thin and crescent shaped. I was standing near the top middle of the crescent, and the high ground gradually diminished, and then disappeared as it reached out toward the far arms of the crescent. This narrow upland surrounded an expanse of marsh.

 

Cat Island beach near the spot where we landed. Note the edge of what was a narrow band of shells and sand to the right and the eroded area toward the left. This point is near the center of the crescent-shaped island and its highest point.

This is a manmade structure, I thought, even before I had a chance to mobilize and sift through all the evidence that led me to this conclusion. I knew from lectures that prehistoric people in this region made shell mounds in certain patterns, and common patterns were semicircles or crescents. Scrambling down I noted the thick layers of shells and sand that made up the ridge of land on which I just stood. It was clear that Cat Island is largely made up of shells, and they are almost certainly shells left by ancient peoples. I also noted that the island was eroding severely. Over-washed, undermined, and uprooted palm trees and other vegetation littered the beach.

 

 

Google Earth image of Cat Island. We landed near the highest point of the crescent-shaped island not far from the southwest facing beach, toward the lower left of the image.

This was one of those islands that are washing away as the result of sea level rise and the series of major storms that visit periodically. Not too many more storms would be needed to make Cat Island disappear completely and become a patch of marsh slowly giving way to open water as sea level rises.

 Walking along the beach to the south and east as the ridge of land narrows, I found another surprise. A large sign faced outward and was obviously intended to be read by passing boaters. It said the island was for sale and included a phone number to contact. Until seeing that sign, I believed that Cat Island was part of the Lower Suwannee National Wildlife Refuge like other islands in the vicinity.  Discovering that this manmade island of likely archaeological significance was private land added to the mystery about the place.

 Surely the refuge must want to obtain such a unique and noteworthy place, particularly because it was for sale and it was difficult to imagine what plans a buyer might have for it. I thought again and wondered what the chances were of finding a buyer when it was so obvious that the island was washing away. But maybe it didn’t matter; everything here would soon be inundated by waters of the Gulf.

 After a quick lunch it was time to leave. The wind had died down, and the paddle back to Suwannee Town was easy and uneventful. It was warm for a December afternoon, and I was only troubled by the fact that my clothing and the padded seat of the kayak were still soaked.

 After we returned, I did some research about Cat Island and discovered that I had heard about the island previously in a presentation by University of Florida archeologists. Conscious that many ancient Native American sites in the region are threatened with inundation by rising seas, the archaeologists were in a race against time, surveying as many sites as possible to learn their secrets before the evidence is lost. Cat Island was surveyed early because of its vulnerability seems so great. Excavations revealed the history of occupation of the site. The role of the crescent configuration of the structure, however, remained a matter of speculation and could be an artifact of shifting sands in the millennium or more since the area was inhabited.

 Years later I learned that sometime after our visit human remains were discovered at the site, doubtless exposed by the erosive forces relentlessly destroying the island and redistributing its parts.

 

More Ferments: Making Sourdough Bread

The Covid-19 pandemic has brought about some changes in people’s behavior worldwide, and it turned out that at least in this part of the world, other people were changing in ways that seemed eerily familiar to us. One example is my decision in mid-summer to try making sourdough bread. Unknowingly I was joining with hordes of other people who have taken up baking during this long period of social distancing. For a while at least, yeast and certain kinds of flour were unavailable in our supermarket. I had become part of a trend, realizing only later that I was part of a near stampede.

Well over a year ago our daughter Meg’s husband Steve began making sourdough, and we were much impressed with the breads he made, although neither Peg nor I harbored any notions of trying it ourselves. Then about the time that I began trying to make sourdough, our other daughter Pam began also. A good neighbor in Virginia gave her some of her sourdough starter, and so she began. Maybe the news of Pam’s early efforts influenced me or perhaps, each of us may have independently stumbled on this new hobby. 

In retrospect, my trying out bread making was a natural; I had gotten interested in fermentation when we began making cheese more than a decade ago while gathering background for The Summer of a Thousand Cheeses. We haven’t tried cheesemaking in a while, but I have regularly made other fermented foods, including sauerkraut, kimchi, and curtido. So why not round out the Random Ferments blog with yet another kind of fermented food product?

I hate being whiny, but the majority of my first five or six tries flopped, producing far less than expected results. The first four resulted in flat, tough hockey pucks, and a fifth was better, but still only slightly resembled a loaf of bread. The first few were made with special bread flour recommended by Steve ($40 for 10 pounds), that despite the pedigree of this ingredient, had no magic. Following other instructions, later attempts used regular all-purpose flour. One recipe even called for use of a packet of store-bought yeast to supplement whatever might be provided by the sourdough starter. It obviously didn’t help, as that attempt was another failure. I should note that we ate these early sourdough products, which were tasty but barely recognizable as loves of bread. The fifth or sixth (sorry, but I’ve lost count), produced under daughter Pam’s tutelage and with some of her starter resulted in an acceptable product which, however differed seriously form the loaf she produced, which was taller, lighter, and definitely more bread-like than mine. A sixth, attempting to follow her successful formulas, produced yet another shrunken, hard, but nevertheless tasty product that was more hardtack than bread.

Success at last! The seventh worked well, and I wish I knew why. My first guess was that, following a suggestion in the first of the several sets of recipes I used filtered water. Could it be that our charcoal filtered water removed some essential substance needed for healthy growth of the yeast? That seems unlikely, and the word from others is that occasional unexplained failures in sourdough breadmaking are to be expected. Nevertheless, six disappointing results in a row seems unusual, especially for me who enjoys experimenting with fermentation, has good equipment, and spent a good many years in chemistry labs.

Two recent successful attempts produced decent loaves of bread, but the dough was too sticky and difficult to handle, some of it was inevitably left behind sticking to cookware, and the loaves were misshaped. In mid-November, following the earlier successful attempts I decided to try again using bread flour. That solved at least partially the problem of too fluid and sticky dough, and the last two loaves have exceeded my modest expectations.

 A recent relatively successful loaf of sourdough, attractive to dogs and people alike.

I now think I know why the earlier attempts failed. I believe I did not adequately feed my sourdough starter. Most times of the year our house is warmer than the 68° F. recommended in the recipes I’ve been using. It was 68° this morning when the outdoor temperature had fallen to 47°, but for most of the warmer season our thermostat is set for 79°. That 11° difference could have effectively doubled the rate of metabolism and reproduction of the yeast (anyone with appropriate knowledge could plug the numbers into a formula and calculate the change precisely). So during the warmer months I have likely fed my starter with fresh flour too infrequently, with twice daily feedings perhaps necessary to maintain its activity. So, when it was time to make the dough, the yeast in the starter was mostly depleted and unable to multiply fast enough and metabolize fast enough to produce a rise. Another possibility is that I may have let the first rise of the dough go on too long, again depleting the supply of fresh flour available to produce a healthy crop of yeast.

It has been said that the surest path to true learning is through a series of failures. If that saying is true, I may finally have mastered making sourdough bread. And if my success holds up, it may be time to move on to new challenges, for example trying a sourdough pizza crust.