For nearly all of its history, Mullet Key could be reached only by boat. The thing that changed that, that turned a remote military island into one of the most visited parks in Florida, was not a decision about the island at all. It was a road. The Pinellas Bayway opened on the 21st of December, 1962, the very same day as Fort De Soto Park, and the two have been inseparable ever since.
Pinellas County had bought Mullet Key back from the federal government in 1948, and the dream of a park was old by 1962. But a park you cannot reach is a park in name only, and Mullet Key sat at the far southwestern corner of the county, across open water from everything. Getting there meant a boat. As long as that was true, the old fort and its beaches belonged to fishermen and the occasional excursion, not to the public at large.
The answer was an ambitious piece of mid-century engineering: a system of causeways and bridges flung across Boca Ciega Bay, with the causeway islands themselves dredged up out of the bay bottom. The Pinellas Bayway took shape as two linked state roads, an east-west route between St. Petersburg and St. Pete Beach, and a hooking north-south spur, State Road 679, that ran down through Tierra Verde and across Bunces Pass to the tip of Mullet Key. It opened as a modest two-lane toll road, but it did what no boat schedule ever could: it connected the island to the mainland by car.
The timing was no accident. The Bayway and Fort De Soto Park opened together, on the same December day in 1962, the road and the destination delivered as a single act. The little toll booth on the way to the fort entered local lore, the “ten cent bridge,” and with it a misconception that has never died: that the toll is the price of getting into the park. It is not. The toll goes to the state's department of transportation for the road; the park, for most of its life, charged nothing to enter, and its parking fee is a separate and much later thing. The road and the park have always been two different institutions that happen to share a birthday.
The consequences ran in every direction. The Bayway made Fort De Soto a place that millions could visit, and in time millions did. It also remade the keys it crossed: the dredged islands and the new access touched off the condominium and resort development of Tierra Verde and Isla del Sol that gives the approach its modern look. The road itself grew with the traffic, widened in the 1980s and rebuilt with a high fixed span in place of its old drawbridge in the 2010s. But its essential meaning has not changed since 1962. The Pinellas Bayway is the hinge between the two halves of Mullet Key's story, the lonely military island on one side, the crowded public park on the other, and the road is what swung the island from the first into the second.