Take FL 136 W to I-75 N to exit 460. Keep left, follow signs to Madison, turn left on FL 6 W to Madison Blue Spring State Park.
The Withlacoochee River flows into the Suwannee River at Suwannee River State Park, requiring a 100 yard paddle upstream to the park's boat ramp.  To get there, take FL 136 W to CR 136A to its end. Turn left on US 129 to I 10W to exit 275, US 90 W to the park.