Is this an actual island

No

There is an island on the county property. Here's what our local park ranger had to offer about why "island" is in the name of this park: The area was named in the late 1800s when the Carney brothers purchased the land near their citrus farms. More than half of the county park (where we've kept the landscape natural) is an island which is connected to the northern portion of the property by a causeway. In fact, the area south of the swim area at Big Lake Weir is where the island begins. Come explore the nature trails and see for yourself. :-)