On August 11, 1948, after World War II was over, Mullet Key was sold back to Pinellas County for $26,495.24. That price included the original 271 acres, plus 613 acres which the military had occupied and was not included in the original price. Extensive plans were drawn up, and many dreams became a reality on May 11, 1963, when Fort De Soto Park was officially dedicated.
In 1977, the Fort De Soto batteries were placed on the National Register of Historic Places. A visitor coming to Fort De Soto Park today can view the remains of Battery Laidley and the last four 12-inch M1890-M1 mortars remaining in North America (the only others remaining in the world are in the Philippines). The ruins of Battery Bieglow can be seen in the surf of the Gulf of Mexico southwest of Laidley. Visitors can also notice two weapons which appear to be out of place on the east side of Battery Laidley. These are two 6-inch rapid-fire rifles manufactured by the W. B. Armstrong Company of England. They came from Battery Burchsted on Egmont Key and were a part of the armament of Fort Dade. The gulf shoreline of Egmont Key was eroding severely and the weapons were in danger of being lost. Through the joint efforts of the Army Reserve, the State of Florida, and the Pinellas County Highway and Park Departments, the weapons were saved, refurbished over a two-year period, and mounted in 1980. This action has preserved another segment of the rich history of our area.