Lake Tulane
Avon Park’s most internationally known feature, and almost nobody in the town’s own history writing mentions it.
The lake
A solution lake — a sinkhole basin in the limestone — about twenty-three meters deep and close to perfectly round, on the Lake Wales Ridge at Avon Park. Its depth and its position on a structural high are what matter: sitting up on the ridge, it never dried out and never overflowed, so sediment has accumulated in it continuously for more than sixty thousand years.[grimm-heinrich]
Crosby’s 1888 pamphlet already names Lake Tulane among the township’s lakes, and it was on its banks that a visiting party was “pleasantly entertained for the night by our friend Mr. King, at his residence.”[aphs-lakes]
Why scientists come here
Cores taken from the lake bed hold a continuous pollen record spanning the past 60,000 years — one of the very few such records anywhere in the south-eastern United States, and by some way the best in peninsular Florida.[grimm-1993-pollen]
The record alternates between two states: peaks of pine and peaks of oak and ragweed. The pine peaks line up, in detail, with the Heinrich events H1 to H5 — the episodes when armadas of icebergs surged off the North American ice sheet into the North Atlantic. That correlation, published in the 1990s, was among the first clear demonstrations that abrupt ocean events in the North Atlantic registered on the continent thousands of kilometers away.[grimm-heinrich]
The relationship is antiphase: when the North Atlantic was cold, Florida was wet, and when the North Atlantic was warm, Florida was dry. Later work using hydrogen isotopes from terrestrial and aquatic lipids in the same sediments confirmed it — aridity fell during the cold stadials and rose during the warm interstadials.[psu-heinrich]
In plain terms: the sand ridge Avon Park sits on has been a desert and a pine forest by turns for sixty thousand years, and the switch was thrown by icebergs in the North Atlantic.
Sister Deep-Time Solution Lakes: Tulane and Verona
A claim has circulated locally that Lake Verona is “33,000 years old or more,” often repeated without citation. Research into the radiocarbon literature confirms that Lake Verona was cored independently in April 1985 by Dr. Herbert E. Wright Jr. (University of Minnesota), yielding a radiocarbon age of >33,000 yr BP on basal gyttja at 29.64–29.74 meters depth (WIS-1744, published by Steventon & Kutzbach in Radiocarbon).[steventon-1986]
Together, Lake Tulane (>60,000-year record) and Lake Verona (>33,000-year record) represent a pair of ancient, steep-sided karst sinkholes on the Lake Wales Ridge whose depths allowed uninterrupted organic deposition through the late Pleistocene.[grimm-heinrich][steventon-1986]
The right form of the scientific distinction is: Lake Tulane holds a continuous sediment record extending past 60,000 years, while Lake Verona preserves an independently dated Pleistocene core exceeding 33,000 years. The lake basins themselves originated earlier through karst dissolution in the underlying limestones.
Why it belongs in the town’s history
Two reasons beyond curiosity.
Almost nothing is known about the deep past of the Lake Wales Ridge around Avon Park, and the archaeology is largely inaccessible. The palaeoenvironmental record is not inaccessible at all — it is published, and it describes the landscape that the ridge’s first people walked into. Any account of Indigenous presence here can be grounded in what Lake Tulane and Lake Verona say the country actually looked like.
And it is a genuine distinction. Avon Park has lakes that appear in the international scientific literature on abrupt climate change and Quaternary limnology. The town’s own histories have rarely recognized this distinction.
References
- grimm-heinrich — Quaternary Science Reviews. Evidence for warm wet Heinrich events in Florida. 2006. https://www.sciencedirect.com/science/article/abs/pii/S027737910600165X
- grimm-1993-pollen — Palaeogeography, Palaeoclimatology, Palaeoecology. Pre-Holocene and Holocene pollen records of vegetation history from the Florida peninsula and their climatic implications. 1994. https://www.sciencedirect.com/science/article/abs/pii/0031018294901740
- psu-heinrich — Quaternary Science Reviews. Climate response of the Florida Peninsula to Heinrich events in the North Atlantic. 2018. https://www.sciencedirect.com/science/article/abs/pii/S0277379118302099
- aphs-lakes — Avon Park Historical Society. The Lakes That Shaped Avon Park. 31 August 2026. https://avonparkhistoricalsociety.com/article/149_The-Lakes-That-Shaped-Avon-Park
- steventon-1986 — Raymond L. Steventon and John E. Kutzbach. University of Wisconsin Radiocarbon Dates XXIII. 1986. https://doi.org/10.1017/S003382220002047X
Related
- Entity: Lake Verona
- Finding: Lake Verona’s 33,000-Year Radiocarbon Date
- Entity: the Lake Wales Ridge
- Report: Lake Wales Ridge Geology and Frost Drainage
- Report: Indigenous presence on the Lake Wales Ridge
- Entity: Hotel Verona
Where this comes from
- Evidence
- single-source — One source. Treat as reported, not established.
- Review
- unverified — Drafted from sources but not yet checked by a volunteer.
- Rights
- society
Sources
- Quaternary Science Reviews, Evidence for warm wet Heinrich events in Florida (2006)
- Palaeogeography, Palaeoclimatology, Palaeoecology, Pre-Holocene and Holocene pollen records of vegetation history from the Florida peninsula and their climatic implications (1994)
- Quaternary Science Reviews, Climate response of the Florida Peninsula to Heinrich events in the North Atlantic (2018)
- Avon Park Historical Society, The Lakes That Shaped Avon Park (2026)
- Raymond L. Steventon and John E. Kutzbach, University of Wisconsin Radiocarbon Dates XXIII (1986)
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