Blue Spring State Park covers more than 2,600 acres, including the largest spring on the St. Johns River. Blue Spring is a designated Manatee Refuge and the winter home to a growing population of West Indian Manatees. The spring and spring run are closed during Manatee season, mid-November through March. For centuries, the spring area was home to Native Americans. In 1766 it was visited by Colonial American botanist John Bartram, but it was not until 1856 that it was settled by Louis Thursby and his family. The Thursby house, built in 1872, remains standing. The spring’s crystal clear, 73 degree water can be enjoyed by swimmers, snorkelers, and certified scuba divers with a partner. The river is popular for fishing, canoeing, and boating. Just not swimming with the manatees.