Not much of a hike, but about 3/4 of a mile paddle from the nearest boat launch, if you head out in a straight line.
This one is only accessable by boat. It's probably easiest with a canoe, kayak, rowboat, or other small craft. The water is normally pretty smooth, and there aren't a lot of power boats out there, but you would still want to keep an eye out. Per park regulations you cannot swim to this one. Boat rentals are available at the marina, if you don't have your own and want to give it a try.
Also you're welcome to drive about on the park roads, and there are some interesting places around, but please do not go off the roads. In most areas there are red signs stating that you aren't to take vehicles any further, but sometimes they are missing. If there's any doubt, don't drive there, since you will be driving through State Wildlife Area.
Congratulations to biogirl03 for the FTF.