Saint Johns River

The St. Johns River is the longest river in Florida. It runs 310 miles north from its headwaters at Blue Cypress Lake and the St. Johns Marsh in Indian River County, west of Vero Beach, to the Atlantic Ocean east of Jacksonville at Mayport. Its headwaters sit only about 27 feet higher than its mouth, so the river flows very slowly and has a long tidal backwater. Its watershed covers nearly 9,000 square miles. The Ocklawaha River is its largest tributary. Along a 140-mile middle stretch the river flows through or connects to more than half a dozen natural lakes, ranging from 380 to 40,000 acres. They include Puzzle Lake, Lake Harney, Lake Jesup, Lake Monroe, Lake Beresford, Lake Dexter and Lake George. The navigable channel begins at Lake Monroe near Sanford. The U.S. Army Corps of Engineers dredges and maintains it, and the U.S. Coast Guard maintains the channel markers.

Public access is run by counties, cities and state agencies along the river. Orange County operates the Highway 50 Boat Ramp near Christmas. Volusia Blue Spring State Park has the French Landing Boat Ramp and a canoe/kayak launch near Orange City. In Jacksonville, launches include the Michael B. Scanlon Mayport Boat Ramp. Many parts of the river and its tributaries are no-wake zones that protect manatees from boat strikes. The Florida Fish and Wildlife Conservation Commission marks state-adopted manatee protection zones on the river in Putnam, Lake and Volusia counties. Blue Spring is a designated manatee refuge. Its spring and spring run are closed to boating and all other water activities from about mid-November through March.

About one-third of Florida's manatees spend the winter in Blue Spring's 72-degree water. Each fall, striped bass and sunshine bass leave their cool-water refuges and gather in the river.