Fort De Soto had a second military life, and almost no one remembers it. Long after the great mortars fell silent, the Second World War brought the armed forces back to Mullet Key, not to defend the bay this time, but to practice destroying targets on it. For a few years the quiet island rang with machine-gun fire and the crump of falling practice bombs, and the legacy of those years is still, literally, in the ground.
When the Army abandoned the old fort, the island passed into civilian hands: in September 1938 the Pinellas County commissioners bought a tract of Mullet Key for about twelve thousand five hundred dollars and set out to make it a getaway, complete with a small lodge and ferry service for day-trippers. That peacetime idyll lasted barely two years. As war loomed, the War Department wanted the island back, and in June 1941 the federal government repurchased it, paying the county roughly eighteen thousand four hundred dollars and returning Mullet Key to military status. The lodge era was over almost before it began; the island that had briefly been a holiday spot became a place to rehearse for war.
Mullet Key became the Mullet Key Bombing and Gunnery Range, a sub-post of MacDill Field, the great army air base across the bay at Tampa. Florida's clear skies and open water made it ideal training country; the Tampa area alone fielded three airfields, MacDill, Drew Field (today's Tampa International Airport), and Henderson Field (now part of the University of South Florida), and air crews from around the bay came to ranges like Mullet Key to learn their deadly trade. Here pilots and gunners practiced air-to-ground attack, strafing and bombing marked targets on and around the low island, the same sandy key the fort had once been built to defend now standing in for an enemy. It was repetitive, dangerous, essential work, the unglamorous machinery that turned recruits into combat air crews.
A bombing range is not only the sky above it; it needs people on the ground. A small detachment of military personnel was stationed on Mullet Key to run the range, and among their duties, as the Museum of Florida History records, was to operate the island's radio control tower and to perform the other functions a live range required: marking and maintaining targets, observing and scoring the runs, keeping the range safe and clear, and signaling the aircraft overhead. They were the human counterpart to the soldiers who had sweated through mosquito-ridden tours at Battery Laidley a generation before, another small garrison on the same isolated key, serving a very different kind of war.
One point deserves care, because the wartime history of the Tampa Bay area has attracted some confusion. Mullet Key was a conventional bombing and gunnery range; the ordnance dropped and fired here was practice and live bombs and ammunition, not chemical weapons. It is true that elsewhere in wartime Florida the Army's Chemical Warfare Service handled mustard agent, and that a postwar search of an inland Florida forest turned up scores of buried mustard-gas bombs, but those activities belonged to other, separate sites, not to Mullet Key. This archive draws the line deliberately: the hazard the island actually left behind is the real and well-documented one of unexploded conventional ordnance, and there is no credible evidence of chemical munitions here.
The island never saw enemy action, and with the war's end its military purpose ended too. In 1948 Pinellas County repurchased Mullet Key, for about twenty-six thousand five hundred dollars, and set it on the path to becoming the beloved park of today. But a bombing and gunnery range does not simply revert to a beach. Not every bomb dropped here exploded, and the buried duds have a way of resurfacing: in 1988 a backhoe operator working in the park struck a bomb embedded in the sand, and an Air Force disposal team was called in to destroy it, one of several such finds over the decades. For this reason the U.S. Army Corps of Engineers carries Mullet Key on its rolls as a Formerly Used Defense Site, surveying and clearing the old range so that the families who picnic and swim here are safe from the leftovers of a war fought eighty years ago. The park's own Quartermaster Storehouse Museum now tells this chapter, with displays on wartime Tampa Bay and the bombing range. It is the strangest turn in the island's military story: the place built to fire on an enemy that never came was, in the end, most endangered by its own side's target practice. The real war, meanwhile, was being fought just offshore, beneath the Gulf, by the submarine-hunting patrols the range's own crews flew.