The 2001 Letchworth Auger Survey shows no activity at the Letchworth site in Jefferson County, Florida. Sites along the coastal areas are low in numbers where many more recent sites are inland which may be in part related to the rise in sea level that probably inundated many sites. It is estimated that sea level on the Gulf of Mexico coast of northern Florida had risen 2 m (6.5 ft) over the last 2000 years.
The 2001 Letchworth Auger Survey did not detect activity at the Letchworth site in Jefferson County, Florida. Coastal areas have fewer recent sites compared to inland locations, which might be related to rising sea levels that submerged many sites over the past two millennia. It is estimated that sea level along the Gulf of Mexico coast of northern Florida increased by 2 meters (6.5 feet) during this time.