The Ortega River Inlet
is the Atlantic Ocean entrance to the St. Johns River, the longest river in Florida; it is 310 miles long and runs through or borders twelve counties. 3.5 million People live within the various watersheds that feed into the St. Johns River, as it is Florida's primary commercial and recreational waterway and the center of Jacksonville
. It is a very slow running river and is one of the few rivers in the United States that runs north.