100,000 Years Ago
- The St. Johns was formed approximately 100,000 years ago after land rose along the coast and trapped a portion of the sea inland. However, the river did not take on its current form until only about 5,000-7,500 years ago, after the sea began to rise at the end of the last ice age. The hydrological cycle of the arid peninsula was transformed, resulting in rains that fed the surface flow of the St. Johns and its underground springs. Before the arrival of Europeans to Florida, Native American groups, including the Timucua, had called the river home for thousands of years.