North Florida Aquatic Plant Field Unit — St. Johns River![Map of Fla.](https://webarchive.library.unt.edu/web/20170119002644im_/http://www.saj.usace.army.mil/portals/44/siteimages/InvasiveSpec/ops/2%20-%20St.%20Johns%20River%20Water%20Management%20District%20Map.jpg)
The St. Johns River originates from broad marshlands about 25 miles north of Lake Okeechobee. This northbound river flows 300 miles until it empties into the Atlantic Ocean at Mayport, near Jacksonville.
The St. Johns River originates from broad marshlands about 25 miles north of Lake Okeechobee. This northbound river flows 300 miles until it empties into the Atlantic Ocean at Mayport, near Jacksonville.
South Florida Operations Office — Lake Okeechobee, the Okeechobee Waterway & Associated Tributaries
Lake Okeechobee and the Okeechobee Waterway are located in central and southern Florida. The 451,000-acre lake and 154 mile long waterway extend from the Atlantic Ocean at Stuart, to the Gulf of Mexico at Ft. Myers. The waterway runs through Lake Okeechobee and consists of the Caloosahatchee River to the west of the lake and the St. Lucie Canal east of the lake.