Little Salt Spring is an ancient spring in southwest Florida. The spring is a fascinating spring for many reasons.
Little Salt Spring is a rich archeological site which traces back to the earliest evidence of human existence.
The spring is also one of the only geothermally heated hot springs in Florida, along with nearby Warm Mineral Springs.
Little Salt Spring Details
Important Notes: Little Salt Springs is not open to the public. It’s privately owned and managed by the University of Miami.
Little Salt Spring should not be confused with the popular Salt Springs in Ocala National Forest.
Little Salt Springs is located in southwest Florida, many hours away from Ocala National Forest and Salt Spring.
Click here for a guide to Salt Springs in Ocala National Forest.
Florida has more than one thousand springs, but there are very few springs in southwest Florida.
Almost all of the springs in Florida are located in north or central Florida. This 1960 Sarasota County Water Atlas shows several nearby springs which are not commonly referenced today.
The springs and sinks in this region of Florida are unique, and tend to have unusual features.
Southwest Florida is home to the only geothermal hot springs in Florida, and a high number of submarine springs, also known as underwater blue holes.
Address: Little Salt Spring Address
The entrance to Little Salt Spring is off of W. Price Blvd. in North Port, Florida.
Little Salt Spring is not publicly accessible. Access is only granted with permission from the University of Florida.
Little Salt Spring Name
Little Salt Springs got its name for two reasons.
The “Little” part of Little Salt’s name is a reference to nearby Warm Mineral Springs, which was once called Big Salt Spring, or Warm Salt Spring.
The two springs were located near each other, and Little Salt Spring was smaller than “Big Salt Spring”, so that’s how it was named.
Click here for a guide to the fascinating Warm Mineral Springs.
The “Salt” part of Salt Springs’ name comes from its high mineral content. Magnesium, sodium and other minerals can give spring water a salty taste as is common in many mineral springs in Florida. This salty mineral taste is never as salty or intense as seawater, though.
Not all of Florida’s springs have high mineral content. Salty mineral springs were rare enough that it was historically used as a descriptive characteristic when naming springs, like the popular Salt Springs in Ocala National Forest.
Like ”Blue Springs”, there are several other springs in Florida with “salt” in their name, so it can be confusing to keep them all straight.
Little Salt Spring is a water filled sinkhole. It was formed when the roof of an underground cavern collapsed 15,000-20,000 years ago.
The surface of Little Salt Spring is approximately 250’ in diameter, and the sinkhole is approximately 250′ deep.
The sinkhole has a wide, shallow basin, and a deep vertical shaft. The sinkhole broadens and becomes wider at the bottom.
Little Salt Spring has very low water flow. It is classified as a third magnitude spring.
The source of Little Salt Spring’s water is located deep beneath the earth’s surface. Because it’s so deep, the water is geothermally heated by the Earth’s core.
Another feature of this incredible depth is that the water in Little Salt Spring contains no dissolved oxygen.
The unique oxygen-free water preserves delicate materials like human flesh, fabric and wood for thousands of years.
Hot Spring Vent
Little Salt Spring is a geothermally heated spring.
There are only two known geothermal springs in Florida which are accessible by land. The only other land-based hot spring is Warm Mineral Springs, which is three miles away.
Little Salt Spring is fed by a geothermal hot spring vent, 240 feet deep underwater. The spring water from this vent comes from deep within the earth’s crust. The water source is so deep that the earth’s heat and pressure warm the water. Source
Scientists are not entirely sure about the water’s source, or details. It may be from a pocket or channel of geothermally warmed seawater which circulates beneath the Florida peninsula.
The precise water temperature varies depending on underlying aquifer conditions. Recorded temperatures have reached up to 91 degrees fahrenheit. Source
The hot spring water exits the spring vent and mixes with other, non-heated spring water sources. When mixed, Little Salt Springs’ temperature drops to 72 degrees, which is typical for springs in Florida. Source
“Ultimately from sea water that is incorporated into the deep bedrock of Florida, thousands of’ below the surface. It is heated, chemically modified, its dissolved oxygen is depleted then finally, it rises to the Earth’s surface through water vents. The cycle takes thousands of years.” Source
This unusual spring water feature is a key to Little Salt Springs’ magic. The water comes from so deep within the earth that it is anoxic, meaning that it doesn’t contain any oxygen. Without oxygen, bacteria cannot grow, and ancient artifacts are amazingly well preserved.
Like all of Florida’s springs, Little Salt Springs is a time capsule and a window into our past.
12,000 years ago Florida, and the world, were very different from what we know today.
During that time– called the Pleistocene Epoch– the earth experienced an ice age. Ocean water was frozen in ice, and sea levels were much lower.
With lower sea levels, Florida’s coastlines were further out at sea. The Florida peninsula was about twice as wide as it is today. Little Salt Spring would have been inland, far from the ocean.
Unlike modern Florida’s wet, warm, humid climate, ancient Florida was cool and dry. Fresh water would have been hard to find.
The water inside Little Salt Spring was lower too. Part of the sinkhole was a dry cave, with fresh water down below. It would have been an oasis, and a good place for ancient paleo indians to live.
It would have provided access to fresh water and attracted wild animals, which the early humans could trap and hunt.
Little Salt Spring has occasionally attracted scientific attention, but it’s generally been neglected. Less than 5% of Little Salt Spring has been researched or explored.
The site was added to the National Register of Historic Places in 1979. It was a cover-story in the prestigious academic journal Science in 1979, and was granted research funds by the National Science Foundation. Source
Currently no research is active because the University of Miami will not allocate funding.
“It’s money,” Gifford said. “My understanding is that the new dean here, after evaluating Little Salt Spring, decided he didn’t want to spend the $100,000 a year to maintain it. That’s basic maintenance and the cost of a caretaker.” Source
Archeologists are frustrated. They say that anywhere you look, amazing treasures are waiting under a layer of sediment. There are so many artifacts at this site that discoveries are sometimes made by accident.
A diver could be working on a site, and casually see a wooden tool laying on the ground beside him. Many of the discoveries were found in randomly assigned dig locations.
Most of the artifacts have been found in the most shallow parts of the spring. Amazing treasures are just waiting to be found deeper inside the spring.
It really is a window into the time of the last ice age. There’s almost no other place in the state of Florida where one can go down and fan away a little bit of sediment and be looking right at the ground where people would have been walking 10,000 or 12,000 years ago.
–University of Miami Archeologist John Gifford
The artifacts tell us how ancient humans arrived, survived, and disappeared. These clues may help rewrite the story of how humans first came to America.
Inside Little Salt Springs, researchers have found some of the earliest humans in western hemisphere. This discovery may help solve the question of where earliest humans came from.
It’s possible that the earliest humans to arrive in north America may have come by boat, instead of by the Bering Strait land bridge, as the current narrative suggests.
Amazingly, ancient human tissue, fabric and wooden tools have all been found inside the spring. The delicate materials are protected and preserved by the unique spring water.
An ancient human skull was found with brain matter still intact. Scientists analyzed the skull’s DNA and discovered a new genetic lineage, which had not ever been found in the Americas. Source
“The finds of the site are unparalleled given that the world’s oldest intact preserved human brain was found inside of a seven-year-old child’s skull who lived between 6,000 and 7,000 years ago. The brain was still pliable and even had retained its shape and discernible details. The only thing that had changed through the millennia was its size, as it had shrunken considerably in the Spring’s natural preservation process.” Source
Rare wooden tools have also been recovered. Wooden tools are rare to find because they usually disappear quickly due to rot and decay.
These tools are significant because they help tell us about what life was like for ancient humans, and how they survived.
“Generally, an anoxic environment does not allow microbes and bacteria to live, so decomposition of organic material is greatly reduced. Wooden and other organic tools, as well as animals’ soft tissues and bones, are preserved nearly intact in this environment.” Source
Scientists aren’t sure what the wooden tools were used for because they’re often the only examples ever discovered. But, they can make educated guesses.
Experts think that some of the wooden tools were wooden stakes, to be hammered in the ground. They may have been used to anchor ropes to climb down into the sinkhole. Or, they may have been used for some sort of hunting technique.
Butchered animal remains were also found with rare wooden tools and hunting devices. Several boomerangs were found, similar to the ones used by Australian aborigines.
Some tools were made of deer antler, which was a useful material for ancient humans.
The First Calendar
One piece of antler was notched with 28 precise, careful markings.
Experts think the notches were used as a calendar tool, to count days in the 28 day lunar cycle.
This pattern has been found in other parts of the world, but this would be the earliest example in the western hemisphere.
Ancient jewelry has also been found inside Little Salt Spring.
Green stones were found, along with ancient beads which were carved out of bird bone, among others. Source
“A stone pendant was found in strata that dates it back to 8,000 years ago by archeologist Steve Koski. The green stone that it is made from has no local source and came from at least 600 miles away in the Appellations. It was shaped, polished and drilled with a precision that is staggering when the age of the artifact is taken into account.” Source
Ancient Burial Ground
In a marshy slough nearby Little Salt Spring an ancient burial ground was found with more than 1,000 burial sites.
The burial site evidence, and other artifacts, suggest that the ancient humans were sophisticated and had a religious tradition.
There are also shell middens onsite in a nearby slough, which are commonly found throughout Florida. Source
They had some sort of religion, he said, based on what has been found in burial mounds discovered up and down Florida’s Gulf Coast. “There was nothing primitive about them as human beings” –Archeologist Brent Weisman
In the dry conditions of ancient Florida, fresh water was scarce for both humans and animals. Both were attracted to oasis water sources like Little Salt Springs.
Many extinct animals have been discovered inside the springs, including:
- Giant Ground Sloth
- Sabertooth Tiger
- Florida Bison
- Giant Tortoise
Archeologists found skeletons from four giant tortoises. They had been hunted, butchered and cooked. They were turned upside down over campfires and roasted inside their shells.
The tortoises were as large as their relative, the famous Galapagos tortoise. Source
Lessons for Modern Humans
Little Salt Springs and its ancient time capsule can also help us understand risks which threaten our own existence, like aquifer destruction and groundwater contamination.
Scientists noticed that the Little Salt Spring site seems to have been abandoned suddenly. Why did ancient humans leave?
One theory is that sea levels rose. Salt water contaminated the underground water supply, and the water became undrinkable. Without fresh drinking water, humans could no longer survive in this location. Source
Little Salt Spring was discovered in 1958 by underwater explorers Bill Royal and Eugene Clark.
The divers faced difficult conditions. There were alligators, and access was difficult.
The divers carried heavy equipment and struggled for several miles of dense brush to dive the spring. Today only a tiny portion of the site has been documented.
In the 1950s, until the 1980s, the land surrounding Little Salt Spring was owned by a large real estate development company, the General Development Corp.
The General Development Corporation hired an archeologist named Carl Clausen to research Little Salt Spring.
Clausen was a controversial man.
He published some early findings in the Journal of Field Archeology in 1975, and then things went downhill.
Critics say that he didn’t do the most important part of his job, which is to preserve, document, publish and share his findings. He never delivered on promised research.
Artifacts…were lost, stored haphazardly or improperly preserved, causing them to decay.
“It’s a gruesome tale,” said Barbara Purdy, a University of Florida anthropologist who has written a book about Florida archaeology that includes Little Salt Spring.
Field notes from the 1970s, which could help direct the current work, are not available. The man who led early excavations at the site, Carl Clausen, is not cooperating with Gifford’s research team. Source
An ancient artifact can only ever be found in its natural state once. If it’s moved, and careful documentation isn’t done, priceless clues are lost forever.
Experts estimate that these mistakes lost more than a decade of irreplaceable research into Florida’s ancient history.
Carl Clausen’s bizarre story ended in violent tragedy decades later. He committed murder and became a fugitive. When police found him he was heavily armed, and there was a massive gun battle. The story was covered by the Tampa Bay Times.
Protectors of Little Salt Springs
Many people have given years, and sometimes lifetimes, of service to Little Salt Spring.
In 1982 the General Development Corp. donated Little Salt Spring and 112 surrounding acres was donated to the University of Miami. It was apparently donated with deed restrictions which require the site to be used for education and research purposes.
Over the years, hundreds of people have fallen in love with Little Salt Springs. Some have dedicated great energy, and even their professional lives, to understanding and protecting the priceless site.
Archeologists, including Dr. John Gifford and Steve Koski, among others, have spent decades studying and protecting Little Salt Spring.
The Friends of Little Salt Spring is a non-profit group dedicated to the appreciation and preservation of Little Salt Springs.
Threats to Little Salt Spring
The health and preservation of Little Salt Spring, the priceless archeological site, are in danger.
Like all of the natural springs in Florida, Little Salt Springs is in danger of being ruined. Little Salt Springs is more vulnerable than most because its sensitive water can be damaged by pollution and chemical changes. Source
University of Miami
The University of Miami has been criticized for its handling of Little Salt Spring and refusing to allocate appropriate resources for research.
“Between 1983 and 2004 the property was held by the university… Due to a lack of equipment and funding, no significant research was conducted…”
Sadly, funding for research ran out and exploration stopped again in 2011. Source
One of the biggest threats to Little Salt Spring is that it will be sold, and developed. The University of Miami has looked into selling the spring.
Struggles have arisen over funding, land use and other elements of the transfer. Deed restrictions were imposed when the spring was donated to the University of Miami in 1982, which require the site to be used for education or research. Unable to sell Little Salt Spring, the University of Miami began discussions to donate Little Salt Spring to Sarasota County. Source
The City of North Port
The community of North Port has risen and fallen over the years. It’s a recurring cycle, which often rides along with Florida’s economic booms and busts.
During boom times North Port expands, as out-of-state residents are drawn to the area’s low-cost real estate. Growth often occurs during speculative markets which inevitably turn to busts.
During the boom times, new homes are built, and new residents move in.
The growing population strains the area’s fragile environment. Threats come from many directions.
- Newly built homes spread fertilizer pollution on lawns, which flows underground into the aquifer.
- Septic tank systems spread nitrate pollution into the groundwater.
- Strained public utilities leak sewage into water supplies.
- Industrial pollution leaches into groundwater.
- New residents require more water, which is pumped from the already strained aquifer.
- Cars leak oil, antifreeze and other chemicals onto roads, which are washed into the the environment.
- Natural areas are bulldozed, which prevents water from being filtered as it enters the ground.
Today, satellite views show that highway and residential houses have been built directly beside the Little Salt Spring site.
- North Port
Phone: 781- 267-8659
Little Salt Springs is owned and managed by the University of Miami Rosenstiel School.
Cover Image by Google Maps, Maxar Technologies