The largest spring on the St. Johns River, Blue Spring is a designated Manatee Refuge and the winter home (mid-November through March) to a growing population of West Indian Manatees. For centuries, the spring area was home for Native Americans. In 1766 it was visited by Colonial American botanist John Bartram, but it wasn��t 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. Swimming or diving with manatees is not permitted and is strictly enforced. The river is popular for fishing, canoeing, and boating. River boat tours are available; for reservations, call St. Johns River Cruises at (386) 917-0724. The park has plenty of picnic areas and a hiking trail. For overnight stays, air-conditioned cabins, a full-facility campground, and primitive campsites are available.